NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.

Buzzacott P, editor. DAN Annual Diving Report 2017 Edition: A Report on 2015 Diving Fatalities, Injuries, and Incidents [Internet]. Durham (NC): Divers Alert Network; 2017.

Cover of DAN Annual Diving Report 2017 Edition

DAN Annual Diving Report 2017 Edition: A Report on 2015 Diving Fatalities, Injuries, and Incidents [Internet].

Show details

Section 1DIVING FATALITIES

, , , , , and .

1.1. INTRODUCTION

DAN prepares this Annual Diving Report to raise awareness of the factors that come into play in recreational diving fatalities, in the hope that such information may better inform the diving community. But injury and fatality surveillance is worthless unless it translates into actions calculated to prevent future injuries. We thus encourage every diver to read this section and to think carefully about the data presented here. Look at the factors that affected some divers’ abilities to overcome difficulties. What could have made the difference in those situations? Often, the diver’s own actions could have led to a more positive outcome. Sometimes those actions — such as careful equipment checks — should take place before a diver even enters the water. And once a diver is in the water, there are many actions — such as staying within sight of one’s buddy and remaining within the limits of one’s training and experience — that are key to enjoying a safe dive.

THE DATA COLLECTION PROCESS

The data collection process at DAN starts with identification of diving- and scuba-related deaths through internet alerts; media reports; dive forums; reports from relevant officials, such as county coroners, public safety divers, and county medical examiners; and reports from members of the public. All recreational diving fatalities that occur in the U.S. or Canada are tagged for follow-up, and any deaths of U.S. or Canadian divers that occur in foreign countries are also marked for follow-up. Fatalities outside the U.S. or Canada involving foreign nationals are tagged as no–follow-up.

News reports, mostly online, are monitored constantly for keywords involving diving and scuba deaths. Other sources for notifications regarding fatalities include reports from families of DAN members, as well as from friends and acquaintances of decedents who are aware of DAN’s data-collection efforts. The DAN Medical Services Call Center (MSCC) is also a valuable resource for data on fatalities, as the DAN Medical Services Department assists with the management of any diving event that is called in, whether the victim is a DAN member or not. (Note that the information collected by DAN on nonfatal injuries associated with scuba diving is covered in Section 2 of this report, while information on injuries and fatalities associated with breath-hold diving is covered in Section 4.)

INVESTIGATOR AND MEDICAL EXAMINER REPORTS

Most diving-related deaths in the U.S. are investigated by local law enforcement agencies or the U.S. Coast Guard (USCG), and many are subject to autopsies. These investigative reports and autopsies are integral to DAN’s research into the causes of scuba-related fatalities. Without access to these reports, it would be virtually impossible to compile enough data for analysis.

Each state in the U.S. has its own set of regulations regarding the release of personal health information, on top of the federally mandated HIPAA (Health Insurance Portability and Accountability Act of 1996) Privacy Rule. Some states consider investigative and medical examiner reports to be public information and release such documents readily, while others have more stringent privacy laws. In addition, within a given state, the regulations (and, hence, the ease of procuring reports) can sometimes vary from county to county. As shown in Table 1.2-2, the majority of diving deaths in the U.S. occur in Florida and California. Fortunately, these two states have straightforward protocols for requesting and obtaining copies of reports.

Table 1.2-2. Distribution by state or province of scuba fatalities in the U.S. and Canada, 2015 (n=43).

Table 1.2-2

Distribution by state or province of scuba fatalities in the U.S. and Canada, 2015 (n=43).

Local investigative agencies (sheriff’s and police departments) follow privacy laws similar to those of medical examiners. However, since their reports typically do not contain private medical information, those entities are often able to release reports upon requests under the Freedom of Information Act (FOIA).

Reports for cases investigated by the USCG can now be requested from one central location in Washington, D.C. However, it may take up to two years after an incident before a case is closed and the report is released. The USCG follows FOIA protocols and will not release personal information contained in their reports. A redacted copy, with all personal and identifying information removed, is usually requested. When they’re available, downloaded dive-computer profiles are included in USCG case files.

REPORTS FROM WITNESSES AND NEXT OF KIN

DAN uses its own Fatality Reporting Form to collect data from witnesses and family members. The form may be downloaded from the DAN website (http://www.diversalertnetwork.org/files/FATform.pdf) or requested from the DAN Medical Research or Medical Services Departments. When necessary, a family member of the decedent may be contacted to assist in the data-collection process. They may complete the Fatality Reporting Form and/or provide authorization for the release of the decedent’s autopsy report. The online incident reporting form on the DAN website (https://www.diversalertnetwork.org/research/incidentReport/) can also be used by family members and/or witnesses to report scuba-diving fatalities or to provide additional details regarding already-reported fatalities.

DATA ENTRY AND ANALYSIS

DAN researchers maintain the diving fatality data on a secure server. Once all pertinent information has been gathered and entered into the database, the results are analyzed and published in the DAN Annual Diving Report.

1.2. GEOGRAPHIC AND SEASONAL DISTRIBUTION OF FATALITIES

Despite the extent and rigor of the data-collection process described in Section 1.1, it is impossible to gather information on all diving fatalities worldwide. Reporting of fatalities is not mandatory, and DAN often does not have access to relevant sources of information outside of the United States and Canada.

Worldwide, DAN received notification of 127 deaths involving recreational scuba diving during 2015. This is shown in Table 1.2-1. Only the deaths of 67 US and Canadian recreational diving fatalities were actively investigated by DAN. Reports of 60 dive-related deaths from other regions were recorded but, due to geographical limitations, were not investigated. There were also 13 deaths that were not recreational divers and breath-hold fatalities are covered in Section 4.

Table 1.2-1. Distribution by region and country of scuba fatalities reported to DAN, 2015 (n=127).

Table 1.2-1

Distribution by region and country of scuba fatalities reported to DAN, 2015 (n=127).

Table 1.2-2 shows the geographic distribution of the 43 2015 fatalities that occurred in the U.S. or Canada or their territories. Another 24 fatalities involved U.S. or Canadian citizens who died while scuba diving overseas. As in previous years, Florida again had the largest number of fatalities, followed by California, then Washington.

1.3. AVAILABILITY OF DETAILED INFORMATION

Autopsies — the most thorough source of information on causes of death — were available for 16 of the 67 U.S. and Canadian fatalities (24%). Table 1.3-1 shows the information available in all 67 cases; the body of the decedent was not recovered in 2 cases (3%).

Table 1.3-1. Medical examination data for U.S. and Canadian scuba fatalities, 2015 (n=67).

Table 1.3-1

Medical examination data for U.S. and Canadian scuba fatalities, 2015 (n=67).

1.4. AGE AND HEALTH OF DECEDENTS

The victims in the 67 U.S. and Canadian fatalities were male in 79% of cases (n=53) and female in 21% of cases (n=14). The vast majority of the victims — 91% of males and 93% of females — were 40 years of age or older, and a significant majority — 75% of males and 71% of females — were 50 years of age or older. Figure 1.4-1 shows the age distribution for these 67 fatalities.

Figure 1.4-1. Distribution by age and sex for U.S. and Canadian scuba fatalities, 2015 (n=67).

Figure 1.4-1

Distribution by age and sex for U.S. and Canadian scuba fatalities, 2015 (n=67).

The medical history of the decedents was, in most cases, incomplete or unknown. Any known pre-existing medical conditions that were reported to DAN are listed in Table 1.4-1; in one case it was explicitly reported that the victim had no known medical conditions.

Table 1.4-1. Known medical history of victims of U.S. and Canadian diving fatalities, 2015.

Table 1.4-1

Known medical history of victims of U.S. and Canadian diving fatalities, 2015.

The true prevalence of hypertension and cardiovascular disease among victims is not known. The numbers presented in Table 1.4-1 represent only the cases reported to DAN. In addition to the fact that a medical history was not available for many victims, some of those who were reportedly healthy may have had undiagnosed hypertension, heart disease or diabetes, as is often the case in the general population.

CASE 1-34: A PROBLEM AT DEPTH PROVED FATAL

A 65-year-old male, an experienced diver, was described as being in good health despite reportedly having undergone triple bypass surgery the previous year. The diver descended with his dive group but signaled a problem at 50 fsw (15 msw) depth and ascended. At the surface, the diver began vomiting and lost consciousness. CPR was initiated, along with mouth-to-mask supplemental oxygen. Then the victim was helicoptered to shore, where he was declared dead.

CASE 1-30: EFFORTS FAILED TO REVIVE A 70-YEAR-OLD DIVER

A 70-year-old male diver’s certification and experience level were unknown. He made a one-hour dive from a commercial dive boat, had about a one-hour surface interval, then made a second dive. He was brought to the surface in distress 20 minutes into the second dive. Others on the boat began CPR, lifeguards were notified, and the victim was unconscious when lifeguards arrived. The victim was pronounced dead on the shore.

The body mass index (BMI) of victims was available in 19 cases (28%) — 15 males and 4 females. According to the BMI classifications of the U.S. Centers for Disease Control and Prevention (CDC 2016), 26% of the victims whose BMI was known were classified as normal weight (BMI of 18.5 to ≤25), 37% as overweight (BMI of 25.0 to ≤30) and 37% as obese (BMI of 30.0 or higher). One diver was classed as severely obese (BMI of ≥40.0). This pattern of obesity among victims of scuba fatalities is similar to that found in the U.S. population at large — about 36.5% (CDC 2017). Data for the general scuba population is not available, however, so it is impossible to know if obesity is more or less common in divers than in the wider population and/or if obesity is linked to an increased risk of dying while scuba diving.

CASE 1-77: A DIVER DROPPED HIS WEIGHTS AND SURFACED BUT REDESCENDED

A 52-year-old male was certified and experienced but had a history of hypertensive cardiovascular disease, diabetes and obesity (his BMI was 33). He was with a group of divers but was making his third dive of the day without an assigned buddy. The group descended down an anchor line, then the victim surfaced behind the boat, yelled for help and sank. A crew member entered the water to locate the victim but was unsuccessful. The victim surfaced a second time but then disappeared again. His body was located two days later, after extensive searches by multiple agencies. The victim’s integrated weight pockets had been removed, suggesting an attempt to establish positive buoyancy. The victim’s dive tank still contained 3,400 psi (234 bar) of air, but it is not known whether the valve was open or closed because the recovery diver manipulated the on/off knob before recording its position.

CASE 1-48: A DIVER HAD DIFFICULTY CLIMBING A LADDER IN ROUGH SEAS

A 41-year-old female had a BMI of 43. A week before this trip, she had participated in two training dives in a lake. This was the victim’s first ocean dive and was intended to count toward her certification. The dive group boarded the boat and set out for a reef about five miles offshore. Witnesses described the sea conditions as “rough.” The diver entered the water, and witnesses said she appeared distressed almost immediately. Efforts to assist her out of the water via the boat’s ladder were initially unsuccessful. After several attempts, the dive guide removed her scuba equipment and pushed her up the ladder from below while the boat captain pulled from above. By the time they got the diver onto the boat, she was unconscious. She had no pulse and had stopped breathing, so the boat crew started CPR. The other divers were by that time diving; they were recalled to the boat so it could leave for shore. The diver’s equipment had sunk but was recovered. The tank contained 2,800 psi (193 bar) of air, and the valve was open. The U.S. Coast Guard arrived and gave assistance and EMS met the boat onshore. The diver was pronounced dead at the hospital.

1.5. DIVING CERTIFICATION AND EXPERIENCE

Information about decedents’ dive certification was available in 26 of the 67 cases (39%), as shown in Figure 1.5-1.

Figure 1.5-1. Distribution by dive certification level for U.S. and Canadian scuba fatalities, 2015 (n=67).

Figure 1.5-1

Distribution by dive certification level for U.S. and Canadian scuba fatalities, 2015 (n=67).

The number of years of experience that divers had logged since achieving their initial certification was known in only 14 cases. That information is shown in Figure 1.5-2.

Figure 1.5-2. Years since initial certification for U.S. and Canadian scuba fatalities, 2015 (n=14).

Figure 1.5-2

Years since initial certification for U.S. and Canadian scuba fatalities, 2015 (n=14).

Here are some of the fatalities reported to DAN where inexperience, often in combination with medical issues, likely played a role:

CASE 1-88: CARDIOVASCULAR DISEASE CAUSED A LOSS OF CONSCIOUSNESS AT THE SURFACE

A 58-year-old inexperienced and uncertified male had enrolled in a guided scuba experience. The diver had a BMI of 39 and a history of medical problems, including diabetes, but had supplied a diving medical form signed by a physician. Preliminary instruction took place in the morning, then in the afternoon the diver and his instructor dived to 38 fsw (12 msw) for 29 minutes. They then surfaced and swam to the boat. At the ladder, the victim lost consciousness and was lifted onto the boat, where CPR was started. The victim was pronounced dead at the hospital. An autopsy revealed extensive narrowing of his coronary arteries, and the cause of death was determined to be atherosclerotic and hypertensive cardiovascular disease.

CASE 1-81: RAPID GAS DEPLETION FOLLOWED BY A RAPID ASCENT PROVED FATAL

A 51-year-old male, uncertified and inexperienced, was participating in a check-out dive for an open water training course. The previous day, the victim had aborted his second dive after practicing an ascent and reporting “asthma issues.” On the day of the fatal dive, the victim was diving with an instructor, one-on-one, and reportedly started his final dive with 2,400 psi (165 bar) in his scuba tank. After 15 minutes underwater, having reached a maximum depth of 62 fsw (19 msw), the victim signaled that his tank was down to 500 psi (34 bar). The instructor reported that the victim grabbed him tightly, and they commenced a rapid ascent. At the surface, the instructor released both of their weight belts and started towing the victim toward the dock, while calling for help. A bystander called 911 immediately, and CPR was commenced, but it was unsuccessful.

CASE 1-27: A NOVICE DIVER SUFFERED A CATASTROPHIC LOSS OF BUOYANCY

A 50-year-old female was an inexperienced novice diver, wearing a rented BCD and newly purchased scuba gear, including a 7mm wetsuit, a total of 30 pounds (14 kilograms) of lead weights, and a steel scuba tank. The diver was making her first open water dive since certification two weeks earlier. She was in a group consisting of eight divers plus a divemaster, intent on visiting an artificial reef starting from the shore.

The group descended at about 1:00 p.m. Soon after, a witness on shore called 911 to report a diver in distress at the surface, shouting for help. The other divers in the group surfaced later and noticed the victim was missing. Her body was found by a solo recreational diver four days later, in 35 fsw (11 msw), with both of her integrated weights still in place. The local police department dive team’s recovery diver noted that the victim’s weight belt was rotated such that the quick-release buckle was behind her. The diver had removed one glove and was still holding it in her gloved hand. Her tank had also slipped loose from her BCD, and her power inflator had come away from the corrugated hose. The corrugated hose had an unusual design, in that it was divided into two halves connected by a quick-release mechanism. Three retaining clips for the low-pressure inflator hose were located on either side of the quick release, to further support that connection, but in this case the low-pressure hose was not clipped into place. The victim’s dive computer had recorded an uneventful dive profile until around 18 minutes, when a rapid ascent from 41 fsw (12 msw) to the surface occurred, followed by an immediate redescent to 41 fsw. The equipment inspection report concluded that a catastrophic loss of buoyancy was a significant factor in the fatality.

CASE 1-93: TWO NEW OPEN WATER DIVERS FOUGHT OVER ONE WORKING REGULATOR

A 15-year-old male had been certified as a junior open water diver but did not dive again for more than two years. He then made 20 lake dives one month before making his first ocean dives from a liveaboard boat anchored near an island. The victim made six dives on the first day, including a night dive. The first dive of the second day was for about 20 minutes, to a depth of 45 to 50 fsw (14 to 15 msw). Conditions at the reef were described as “ideal,” with visibility of over 40 feet (12 meters).

For his second dive that day, the victim took a spear gun with him. When the victim’s buddy, who was making his first-ever dive without an instructor, had 1,000 psi (69 bar) remaining in his tank, he started ascending. He looked back down and saw the victim signaling that he needed to share air, so he returned to depth and donated his back-up regulator. The pair started ascending together, but at 70 fsw (21 msw) the victim removed the back-up regulator and pulled his buddy’s primary regulator from his mouth. After watching the victim take two full breaths, the buddy concluded the victim was not going to return his regulator, so he pulled the low-pressure hose to forcibly reclaim his regulator from the victim’s mouth.

The buddy saw the victim fall away rapidly without moving his arms; then he also ran out of gas, surfaced rapidly, and suffered a seizure, requiring first-aid oxygen and subsequent hyperbaric oxygen therapy at the nearest chamber. Meanwhile, the victim had aspirated water and landed on the bottom, unconscious. Two divers happened upon the victim after spotting his speargun lying on the sand at 94 fsw (27 msw) and ascended with him. CPR commenced as soon as the victim was back aboard the boat. The U.S. Coast Guard and the local sheriff’s dive team arrived within minutes; the victim was transported to a nearby medical facility, where he was pronounced dead.

1.6. CHARACTERISTICS OF FATAL DIVES

PRIMARY ACTIVITY

The primary activity was reported for 49 of the 67 fatal dives (73%) during 2015. For almost half of them (32, 48%) it was pleasure or sightseeing; 7 (10%) were training dives (not necessarily involving a student, however), and 5 (7%) involved spearfishing, hunting or collecting game. Figure 1.6-1 shows the distribution of primary activities during fatal dives in 2015.

Figure 1.6-1. Primary dive activity during U.S. and Canadian scuba fatalities, 2015 (n=67).

Figure 1.6-1

Primary dive activity during U.S. and Canadian scuba fatalities, 2015 (n=67).

DIVE PLATFORM

In most cases, fatal dives began from a charter boat or private vessel (n=35, 52%). Dives began from a beach or pier in 19 cases (28%). Figure 1.6-2 shows the platform from which fatal 2015 dives began.

Figure 1.6-2. Dive platform for U.S. and Canadian scuba fatalities, 2015 (n=67).

Figure 1.6-2

Dive platform for U.S. and Canadian scuba fatalities, 2015 (n=67).

Here are a couple of the fatalities reported to DAN where the dive platform may have been a factor:

CASE 1-74: A DIVER MADE A GIANT-STRIDE ENTRY WHILE THE BOAT THROTTLE WAS ON

A 61-year-old male, a certified and experienced diver, was on a dive vacation with nine other divers. Conditions were described as “choppy,” so the divers made a giant-stride entry. The dive guide entered the water at the same time as the victim. When the dive guide looked up, he saw the victim underneath the platform at the rear of the boat and blood in the water. The victim was brought back on board; he appeared to have been struck in the head, by either the propeller or the platform. The victim was unconscious and had aspirated water. He was taken to the local hospital, where he underwent surgery and fluid was drained from his lungs. He was then repatriated to a hospital in the U.S. but died within days.

CASE 1-90: A LEFT-BEHIND DIVER’S NAME WAS MISSING FROM THE ROLL

A 45-year-old female was a well-known regular aboard a certain dive boat. The divers entered the water and descended to hunt for lobster. The victim was last seen descending from the boat, at a depth of 15 fsw (5 msw). When the divers returned to the boat, a roll was called — but four divers’ names were missing from the roll, including that of the victim, so those names were not called out. The boat left for another dive site, and the victim was not seen again.

ENVIRONMENTAL FACTORS

There are several environmental factors that may play a role in fatalities, as follows:

  • Type of water: Most fatal dives in 2015 occurred in an ocean/sea environment (n=45, 67%), though a significant minority occurred in stationary fresh water (n=9, 13%) or in rivers or springs (n=6, 9%). Seven cases (10%) did not include a description of the dive environment.
  • Visibility: This factor was reported in only 13 of the 67 cases (19%). It was excellent (>50 feet [15 meters]) in 4 cases (6%), moderate (10–50 feet [3–15 meters]) in 7 cases (10%), and poor (<10 feet [<3 meters]) in 2 cases (3%). Visibility in the remaining 54 cases (81%) was unknown.
  • Sea conditions: This factor was reported in 16 of the 67 cases (24%). Calm seas were noted in 5 cases (7%), moderate seas in 4 cases (6%) and rough seas in 7 cases (10%).
  • Current: The presence (or lack) of a current was noted in 10 of the 67 cases (15%). The reported currents were strong in 5 cases (7%), slight in 3 cases (4%) and none in 2 cases (3%).
  • Time of day: This factor was reported in 48 of the 67 cases (72%). All of those occurred during daylight hours.

This is an example of a fatality where environmental factors were clearly an issue:

CASE 1-27: CONDITIONS OVERWHELMED A VISITING DIVER

A 27-year-old male diver had been certified for eight years and held advanced open water and nitrox certifications, though his log book indicated that he had made only 14 dives, the most recent of them one month earlier. While visiting from overseas, he rented dive equipment and was diving from a boat with a guide and four other divers in an area known for strong currents. The water was just 45°F (7°C), though the victim was wearing a drysuit. The victim and the guide dived to 40 fsw (12 msw) for approximately 17 minutes, before the victim signaled that he was down to 1,000 psi (69 bar) of air. The pair commenced their ascent, but the guide later reported that they had difficulty resisting a downward current (also known as a back eddy), and they had to kick hard to ascend. At 20 fsw (6 msw), the victim was down to 500 psi (34 bar), and the guide was holding on to the victim as they continued to ascend. At around 9 fsw (3 msw), they encountered some kelp, and the guide signaled for the victim to hold onto him while he untangled the kelp from his regulator. The victim let go of the guide and was last seen being carried away by a strong undertow. His body was recovered seven weeks later, after being spotted on the surface not far from the dive site.

EQUIPMENT AND GEAR

There are many sorts of equipment and gear considerations — especially proper maintenance — that can play a role in fatalities. It is often difficult to gather such information after the fact, however. Information about protective suits worn by divers involved in fatalities was available in 24 of the 67 cases (36%). Of those, 15 victims (22%) wore wetsuits, 3 (4%) wore swimsuits or dive skins, and 6 (9%) wore drysuits.

Here is an example of a fatality in which the diver’s equipment appeared to have been a central factor:

CASE 1-99: A DIVER WENT DEEP WITH NEW EQUIPMENT AND RAN OUT OF GAS

A 59-year-old male had a number of dive certifications, but this was his first dive since the previous year. He was testing out a new dry-suit and a new dive computer. He had planned to dive solo, but he found another diver who needed a buddy. They were ascending from a 130-ffw (40-mfw) bounce dive when, shortly after a brief stop at 65 ffw (20 mfw), the buddy noticed the victim struggling with his equipment. He nonetheless indicated that all was okay. At approximately 20 ffw (6 mfw), the victim was again seen struggling with his equipment, this time with his mask. The buddy assumed the victim was not getting enough air, so he gave him his primary air source and switched to his secondary. The victim lost consciousness before they reached the surface.

The buddy brought him up and started emergency rescue procedures. EMS arrived when the victim was out of the water; by that time, he had no pulse and was not breathing. He was pronounced dead at the local hospital. Inspection of his equipment showed that it was poorly maintained, that the primary tank was empty and that the pony tank was mounted in such a way that the second stage could not reach the diver’s mouth.

MAXIMUM DEPTH

The maximum depth of a dive is another factor that can be involved in fatalities. In 27 of the 67 investigated cases (40%), the maximum depth of the fatal dive was reported; 5 of those cases (7%) occurred in water up to 30 feet (9 meters) deep, 8 cases (12%) in water 31–60 feet (9–18 meters) deep, 3 cases (4%) in water 61–90 feet (19–27 meters) deep, 6 cases (9%) in water 91–120 feet (28–37 meters) deep, and 5 cases (7%) in water deeper than 120 feet (37 meters). Depth data were not available for 40 cases (60%). Figure 1.6-3 shows the depth distribution of fatal dives in 2015.

Figure 1.6-3. Maximum depth by sex for U.S. and Canadian scuba fatalities, 2015 (n=26).

Figure 1.6-3

Maximum depth by sex for U.S. and Canadian scuba fatalities, 2015 (n=26).

Here is an example of a fatality in which the depth of the dive was clearly a factor and perhaps the primary cause.

CASE 1-68: A WORLD-RECORD DEPTH ATTEMPT ENDED IN DEATH

A 56-year-old male, an experienced diver, was attempting a world-record open-circuit dive to 1,200 fsw (366 msw). He had previously dived to a depth of 815 fsw (248 msw). According to news reports, he expected to descend rapidly down a 1,300-foot (396-meter) descent line weighted by a 250-pound (113-kilogram) anchor, clip a marker onto the line at the 1,200-foot (366-meter) mark, then start his ascent immediately. The plan was that he would meet with support divers at 350 fsw (107 msw) on his return from depth, an estimated 38 minutes after his initial descent. The intent was that the line would then be retrieved, and the position of the marker would confirm the depth he had reached. The diver was reportedly wearing seven scuba tanks of various sizes, with another 28 tanks on site. The dive plan, including decompression, was for the diver to be underwater a total of 10.5 hours. After his descent, the support divers moved into their agreed-upon positions along the ascent line, starting at 350 fsw (107 msw) depth. However, the victim failed to arrive at the appointed time. The support team waited but eventually had to surface. The diver’s body was recovered a few days later, when a vessel capable of raising the rope and anchor arrived on site.

GAS TYPE AND BREATHING EQUIPMENT

In only 20 of the 67 cases (30%) was it known what type of breathing gas the victim was using. In 15 of those cases (22%), the victim was using air. The type of breathing gas involved in 2015 fatalities is shown in Figure 1.6-4.

Figure 1.6-4. Type of gas used in U.S. and Canadian scuba fatalities, 2015 (n=67).

Figure 1.6-4

Type of gas used in U.S. and Canadian scuba fatalities, 2015 (n=67).

Open-circuit scuba equipment was used in 50 of the 67 cases (75%), rebreathers in 4 cases (6%) and surface supply in 1 case (1%). The breathing unit involved in the remaining 12 cases was unknown. Figure 1.6-5 shows the type of breathing equipment used.

Figure 1.6-5. Type of breathing equipment used in U.S. and Canadian scuba fatalities, 2015 (n=67).

Figure 1.6-5

Type of breathing equipment used in U.S. and Canadian scuba fatalities, 2015 (n=67).

The following case illustrates the role breathing equipment can play in fatalities:

CASE 1-56: A HOOKAH STOPPED AND DIVERS MADE RAPID ASCENTS

A 37-year-old male, who reportedly lacked formal certification but did have diving experience, was diving with a buddy to spearfish. They were using a surface-supplied hookah diving system but were not carrying redundant air sources. It was their second dive of the day, to 80 fsw (24 msw). The hookah diving system had not been refueled between the two dives; it ran out of fuel during the second dive and stopped supplying air to the divers. The victim, along with another diver, made a rapid ascent to the surface. The victim became unresponsive upon surfacing. He was recovered by the nondiving occupants of the boat, and CPR was administered, but he was pronounced dead on shore. The medical examiner’s report indicated that the victim had suffered significant injuries consistent with lung overexpansion.

DIVE BUDDY STATUS

While at least 8 (12%) of the 67 fatal dives were intended as solo dives, most of the 2015 fatalities began as buddy dives. Adherence to buddy-system best practices is difficult to establish retrospectively. When survivors notice that their buddy is missing, it does not necessarily mean that the buddy became intentionally separated; rather, it may mean that nobody noticed the diver was having the problems that eventually led to the fatality. Yet either circumstance indicates a failure of the buddy system. Figure 1.6-6 shows the distribution of fatal dives according to buddy status.

Figure 1.6-6. Buddy status during U.S. and Canadian scuba fatalities, 2015 (n=67).

Figure 1.6-6

Buddy status during U.S. and Canadian scuba fatalities, 2015 (n=67).

Here is an example of a fatality in which buddy status played a role:

CASE 1-65: SILT CAUSED AN UNPLANNED SEPARATION AND A FATAL DELAY IN EXITING A CAVE

A 68-year-old male, an experienced and certified cave diver, had completed several dives in the same cave system prior to the fatal dive. The diver and his buddy entered the cave system with two primary tanks each, one diver propulsion vehicle (DPV) each, and a decompression tank each, which they staged near the exit. The divers scootered to around 3,000 feet (900 meters) penetration and then left the main line to explore a side passage. The victim was wearing his primary tanks on his back, while his buddy was wearing hers on either side. The pair entered a low section of cave, where the floor was covered in mounds of dark silt. Visibility was suddenly compromised, and the divers lost contact with each other. The buddy found her way back to the main line and reported waiting for three to four minutes before leaving for the cave exit. By the time the victim returned to the main line, leaving his DPV in the side passage behind him, his buddy was gone and the victim started the long swim out. At the time, they were the only dive team in the cave. Meanwhile, the buddy surfaced and notified officials. A team from International Underwater Cave Rescue and Recovery arrived on site, entered the cave, noted the decompression tank just inside the entrance, and found the victim about 300 feet (90 meters) from the exit, his tanks empty.

1.7. ANALYSIS OF SITUATIONS AND HAZARDS

We classified each fatality that we investigated according to the phase of the dive during which the incident occurred and also recorded the chronological chain of events that ended in death.

FATALITIES BY DIVE PHASE

The dive-phase categories are as follows: a) on the surface before diving, b) underwater, c) on the surface after diving, and d) exiting the water. Dive-phase information was available in 40 of the 67 cases (60%). Figure 1.7-1 shows the phase of the dive when the victim lost consciousness. As can be seen, in the majority of fatalities this occurred either underwater (n=18, 27%) or on the surface following the dive (n=17, 25%).

Figure 1.7-1. Dive phase when the victim lost consciousness in U.S. and Canadian scuba fatalities, 2015 (n=67).

Figure 1.7-1

Dive phase when the victim lost consciousness in U.S. and Canadian scuba fatalities, 2015 (n=67).

This case is an example of a fatality that occurred on the surface after completion of a dive:

CASE 1-39: BOAT COULDN’T REACH A LONE, STRUGGLING DIVER

A 65-year-old male was on a guided dive to 40 fsw (12 msw). He reportedly separated from the dive group to surface alone. At the surface, he was seen struggling to get to the tag line. He sank before anyone on the boat could reach him to offer assistance. His body was recovered three hours later.

CAUSES OF INJURY AND DEATH

DAN’s determination of the causes of these reported fatalities was based on the following sources of information: a) the autopsy findings and/or the underlying cause of death as reported by a medical examiner; b) the victim’s dive profile; c) the sequence of events as reported by witnesses; d) the findings from analyzing the victim’s equipment and gas supply; and e) the expert opinions of DAN reviewers. This process is described in further detail in a published paper (Denoble et al. 2008).

The 2015 fatalities’ root causes (also known as triggers, mechanisms, disabling injury, and causes of death), could not be established in 33 of the 67 cases (49%), mostly because of missing information and inconclusive investigative results. Among the 34 cases (51%) for which such information was available, the most common triggers were an underlying health problem (15%) and running low on or being out of air (6%). Table 1.7-1 lists all triggers that could be identified.

Table 1.7-1. Triggers for U.S. and Canadian scuba fatalities, 2015 (n=34).

Table 1.7-1

Triggers for U.S. and Canadian scuba fatalities, 2015 (n=34).

The most commonly identified harmful events, or actual mechanisms of injury, were underlying health problems (12%) and insufficient breathing gas (9%). Table 1.7-2 lists all the known mechanisms.

Table 1.7-2. Mechanisms of injury for U.S. and Canadian scuba fatalities, 2015 (n=34).

Table 1.7-2

Mechanisms of injury for U.S. and Canadian scuba fatalities, 2015 (n=34).

In most of these 34 fatalities, the cause of death as established by medical examiners was drowning. However, according to DAN’s expert reviewers, the data indicated that a leading cause of disabling injuries was an acute cardiac event. Tables 1.7-3 and 1.7-4 list these 34 fatalities’ disabling injuries and causes of death, respectively, while Figure 1.7-2 compares disabling injuries and causes of death side by side. These presentations of the data show clearly that in 2015, the leading cause of death was drowning and the leading disabling injury that led to death was heart problems.

Table 1.7-3. Disabling injuries in U.S. and Canadian scuba fatalities, 2015 (n=34).

Table 1.7-3

Disabling injuries in U.S. and Canadian scuba fatalities, 2015 (n=34).

Table 1.7-4. Causes of death in U.S. and Canadian scuba fatalities, 2015 (n=34).

Table 1.7-4

Causes of death in U.S. and Canadian scuba fatalities, 2015 (n=34).

Figure 1.7-2. Most common causes of death (n=28) and disabling injuries (n=21) in U.S. and Canadian scuba fatalities, 2015.

Figure 1.7-2

Most common causes of death (n=28) and disabling injuries (n=21) in U.S. and Canadian scuba fatalities, 2015.

These two cases illustrate the complex interplay between the disabling injury and the cause of death in incidents that result in a fatality:

CASE 1-07: A LONE DIVER SUFFERED HEART PROBLEMS

A 66-year-old male with unknown certification and experience had an arrangement with a local landowner to park his truck near a beach from which he frequently dived alone. He was last seen alive two hours before his body was found floating on the surface by kayakers. Investigators were called to the scene. According to a news report, heart problems were a factor in the death, which was ruled an accident by the coroner’s office.

CASE 1-33: ANTIDEPRESSANTS WERE RULED A CONTRIBUTING FACTOR

A 41-year-old female had been diving for 23 years and had made more than 400 dives. She had experience in a variety of diving conditions and was certified as both a divemaster and a nitrox diver. Her most recent dive medical examination had been performed three years earlier. She was being prescribed fluoxetine (also known by the brand name Prozac), a drug commonly prescribed for treating depression. This dive was in a popular flooded quarry, and the plan was for a group of four divers to navigate underwater between manmade objects. About 40 minutes into the dive, the victim calmly pointed to her pressure gauge, pointed to her chest, and gave a thumbs-up signal, then pointed at the other divers and made a “shooing away” motion. The diver then waved goodbye and moved away toward the exit point. The other members of the group surfaced approximately 20 minutes later. They could not see the victim and noticed her gear was not at their vehicle, so they alerted the facility staff and called EMS personnel. Two members of the group re-entered the water and found the victim in 50 ffw (15 mfw) after about 11 minutes of searching. The victim was returned to the surface an hour and 20 minutes after last being seen alive. Her pressure gauge indicated her tank was empty. The autopsy found markedly high levels of fluoxetine, and the cause of death was ruled to be drowning, with fluoxetine toxicity a contributing factor.

Fluoxetine is sold under a number of brand names, including Prozac and Sarafem. In 2010, more than 24 million prescriptions for generic fluoxetine were filled in the U.S. The U.S. Food and Drug Administration recommends a starting dose of 20 mg/day and a maximum dose of 80 mg/day, but the pathology report in this case indicated the diver had taken far in excess of the recommended maximum safe dose. It was reasonable, therefore, for the medical examiner to conclude that the diver was likely impaired and that this was a contributing factor in the drowning.

DAN receives many inquiries concerning antidepressants, and this case serves to highlight the fact that divers may not fully understand what is happening inside their dive buddies, even when a dive seems uneventful. DAN recommends that whenever a diver signals that they intend to exit, a buddy or team member should escort the diver to the exit point and see them safely out of the water.

1.8. REBREATHER FATALITIES

DAN is aware of four recreational diving rebreather fatalities in 2015 that occurred in the U.S. or involved a U.S. citizen whose body was repatriated to the U.S. Three of those cases are described below.

 

CASE 1-25: THE CURRENT WAS TOO STRONG FOR A REBREATHER DIVER

A 53-year-old male, a certified and experienced technical diver, was participating in an annual technical diving event. An hour into the dive, the victim reportedly experienced difficulties with a strong current and was assisted to the surface by his buddy. The victim was unconscious by the time they reached the surface. The buddy signaled for assistance, the pair were collected by a dive boat, and CPR was performed while the boat headed for shore. An ambulance took the victim to the hospital, where he was pronounced dead.

CASE 1-91: A REBREATHER DIVER LIKELY FORGOT TO TURN HIS VALVE ON

A 57-year-old male had been trained on a rebreather (though to what level is unclear) and had made a total of about 2,000 open water dives. He had not consistently dived with his rebreather since achieving certification two years earlier, however. He was an active open water dive instructor and had booked dives on a dive charter boat to explore a shipwreck in 150 fsw (46 msw). He was without a buddy and was believed to be using a brand new DPV that he had used only once before, in a pool. He was also using a drysuit for the first dive in some time, because he had recently been training students while wearing a wetsuit. Another diver on the boat was using the same model of rebreather and the same type of DPV, so these two divers buddied up.

The victim delayed getting into the water, taking about 15 minutes to don his equipment, and entered the water with a partial pressure of oxygen (ppO2) of 0.22 bar. The set point on his electronic handset was 0.19 bar. The victim then surprised his buddy by engaging his DPV for the descent, rather than using the descent line. The victim descended without conducting buddy or bubble checks.

The pair lost sight of each other for the first 10 minutes of the dive, then the buddy spotted the victim near the wreck. When the buddy saw the victim, he appeared to be having trouble and was using his bailout open circuit regulator instead of his rebreather. By the time the buddy reached the victim, there were no bubbles coming from his regulator and the victim appeared to be unconscious. The buddy pressed the victim’s purge button but no gas came out, and the victim’s submersible pressure gauge indicated that his bailout tank was empty. During the rescue, attempts to inflate the victim’s buoyancy compensator device (BCD) were unsuccessful, and it was discovered that the victim’s diluent valve was closed. The buddy opened the valve to inflate the victim’s BCD.

The victim was sent ahead to the surface, feet first, while the rescuers and the buddy completed their decompression stops. The victim was recovered at the surface and swiftly taken to the nearest hyperbaric chamber but was pronounced dead shortly after his arrival there. The ppO2 displayed on his dive computer reached 2.50 bar before falling during the dive, indicating that his oxygen valve was turned off at depth (it is of note that 2.50 bar is the maximum possible value displayed by his model of dive computer, even if ppO2 levels are higher). Estimates, based on the recorded millivolt output from the oxygen sensors in his dive computer, suggest that the ppO2 in his breathing loop when he reached 151 fsw (46 msw) was likely around 4.8 bar. None of the warnings displayed by his dive computer, from one minute into the dive onward, were acknowledged by the victim pressing a button on his handset.

It is thought that the victim descended with his diluent valve closed. During testing of his equipment, it was discovered that his diluent valve could not be turned on while someone was wearing the unit, because the drysuit inflator valve obstructed access to the diluent value. The victim had apparently arrived at depth, bailed out to a 40-cubic-foot tank, was unable to inflate his BCD, ran out of gas, and drowned while wearing a fully functioning rebreather with one of its valves turned off. The dive computer worn by the victim logged a total dive time from surface to depth to resurfacing of 21 minutes.

CASE 1-95: A DIVER FELT UNWELL BEFORE LOSING CONSCIOUSNESS AT THE SURFACE

A 54-year-old male was diving with a rebreather in a flooded quarry. The diver’s certification and experience level were unknown. The victim complained of feeling unwell before the dive but decided to dive anyway, putting his stomach’s uneasiness down to his previous night’s meal. According to investigative reports, the victim initially went into the water with a friend, then signaled that he planned to surface a short time later. At the surface, he indicated that he still felt unwell, then descended without his rebreather loop in his mouth. The buddy grasped the victim, towed him to shore and then called emergency services. The main findings at autopsy included an enlarged heart, heart disease and plaque-obstructed arteries. There were no findings suggestive of drowning or gas emboli. Toxicology tests found no signs of recreational drugs or alcohol. The victim’s equipment was checked by an expert who found a small gas leak; however, the tank still had residual gas, which was tested and shown to be a normal mixture.

The symptoms this diver experienced before the dive were probably related to acute coronary syndrome, but the diver may not have recognized them.

All divers should remember that it is important not to dive if they feel unwell, regardless of the possible or assumed cause. And divers over 45 should be familiar with the symptoms of acute heart problems and should seek evaluation if they ever experience such symptoms.

1.9. DISCUSSION

This year’s “Fatalities” section highlights data in support of the messages that DAN consistently communicates to the diving community. Divers, like the population in general, are getting older and heavier. And, being human, divers sometimes make mistakes. While many of the cases in this year’s “Fatalities” section appear (with hindsight) to have been preventable, some cases involving older victims had no obvious provocative or contributive factor.

No one wants to police recreational divers, but a quiet word when someone is about to make a poor decision should be tolerated by most divers. It is high time for the diving community to fully embrace a culture of safety, a culture where predive checks become as routine and expected as safety stops have become. Checklists have gained popularity among rebreather divers, and, just as the octopus regulator was pioneered in cave diving but has moved into mainstream diving, DAN sincerely hopes checklists will move beyond technical diving and into mainstream diving.

Shortcomings in personal fitness, stamina and general health again seem to have played a role in some of this year’s fatalities. The sea is an unforgiving playground. While obese divers may be able to manage recreational diving when conditions are benign, if the current picks up or surface conditions deteriorate, then, all else being equal, a fitter diver will be better able to cope. If we love diving as a lifestyle, if we look at dive magazines and imagine ourselves drifting over pristine coral reefs, if we proudly tell our friends that we’re going scuba diving on vacation, then we owe it to ourselves, our family and those we care for to stay in shape for diving. Start today. Let being fit to dive be your motivation to succeed. You will likely see your air consumption improve, too.

In addition, given that cardiovascular problems remain a significant contributory factor in many diving fatalities, DAN encourages every diver to know the signs and symptoms of acute heart problems. Procedures for the medical evaluation of fitness to dive may be due for updating to account for the aging diver population and thus the increased prevalence among divers of medical conditions associated with aging.

This Annual Diving Report contains the lowest number of American and Canadian recreational scuba fatalities in more than 20 years, but that does not necessarily mean diving is getting safer. The British Sub-Aqua Club also reported a 20-year record low number of deaths for 2015 among its membership. Perhaps we, as a community, are getting better at diving safety? However, as in the U.S., it is thought that British divers are getting older (Cumming and Peddie 2015). So perhaps it is more likely that, as a community, we are not making as many dives each year. It must also be noted that, while every effort is made to compile the most accurate data available, we nonetheless do sometimes hear about a small number of diving fatalities years after they happened. The numbers presented in the DAN Annual Diving Report do not change much after the reports are published, but they never decrease — they can only increase.

Rebreathers continue to gain popularity, and this year’s report again highlights the fact that common triggers for rebreather deaths include both pre-existing medical conditions and simple human error — such as in Case 1-91 (see page 25), where a diver likely forgot to open his diluent valve. Other contributing factors in that case may have included new equipment, a configuration that prevented opening the valve during the dive, a failure to complete a predive checklist, a failure to make buddy and bubble checks, the use of a DPV instead of a descent line to descend — the list of possible factors goes on. Rarely does a single mistake kill a diver; most fatalities culminate from incremental increases in risk and/or incremental reductions in a diver’s likelihood of surviving, until the tipping point is reached and the diver is unable to recover. This is where a culture of dive safety that engages everyone in our community, at all levels, increases safety — through many incremental reductions in risk.

Buddy checks, checklists, clear dive plans, gas planning, maintenance of dive skills, properly equipping yourself for every dive, staying fit to dive: all these steps reduce risk, so we can keep diving safely, year after year.

REFERENCES

  • CDC (U.S. Centers for Disease Control and Prevention). “Defining Adult Overweight and Obesity.”. 2016. Accessed August 23, 2017. https://www​.cdc.gov/obesity​/adult/defining.html.
  • CDC (U.S. Centers for Disease Control and Prevention). “Adult Obesity Facts.”. 2017. Accessed September 20, 2017. https://www​.cdc.gov/obesity/data/adult​.html.
  • Cumming B, Peddie C. National Diving Committee Diving Incidents Report 2015. Cheshire, England: British Sub-Aqua Club; 2015.
  • Denoble PJ, Pollock NW, Vaithiyanathan P, Caruso JL, Dovenbarger JA, Vann RD. “Scuba injury death rate among insured DAN members.” Diving Hyperb Med. 2008;38(4):182–8. [PubMed: 22692749]
© 2017 Divers Alert Network.

This work is available under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Bookshelf ID: NBK487743

Views

  • PubReader
  • Print View
  • Cite this Page
  • PDF version of this title (3.9M)

Other titles in this collection

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...