Background
- Two divers (50-60s) with 53 & 72 ft3 aluminum open circuit SCUBA.
- Two dives were performed in an overhead environment (cavern).
- On the second dive, one diver surfaced and was found to be deceased. The second diver was later found at a depth of 137 feet near the permanent cave line.
- Both divers had no gas remaining in their cylinders.
Reported Incident
Two divers arrived at Buford Sink, a cavern within the Chassahowitzka Wildlife Park at approximately 11:00 am. While the two divers set up their gear, they chatted with some juvenile bystanders who had come to the sink to swim and hang out by the water.
After resurfacing from the first dive, the bystanders overheard the two divers discussing if they had adequate gas to return for a second dive to 140 feet in the “cave”. Diver A was also overheard discussing a possible leak coming from his cylinder.
The two divers then submerged for a second dive between approximately 11:45am and 12:00pm. A short while later, the bystanders observed Diver B floating on the surface face down. The bystanders interpreted this as the diver intentionally looking down for his buddy. However, after noticing that bubbles were no longer coming to the surface, they swam over to Diver B. Upon noticing that Diver B was not breathing, they notified law enforcement at approximately 12:20 p.m. and pulled the diver towards the dock but were unable to extricate the diver.
International Underwater Cave Rescue and Recovery (IUCRR) was notified at approximately 12:26pm and arrive at approximately 2:15pm to assist in victim recovery and equipment analysis. Both divers were recovered with little to no remaining gas in their cylinders.
Equipment Configuration
All SCUBA equipment was examined and found to be functioning. Diver A’s cylinder had a slight leak where the yoke first stage regulator meets the tank valve. However, after readjusting the yoke, the leak stopped suggesting that the O-ring had sealed properly.
Review
Extensive training and proper equipment are required for dives that occur in overhead environments or at depths beyond the recreational limit of 130 feet. Buford Sink has a large cavern area that extends beyond 130 feet as well as a cave system for those with the proper training and equipment. Although it is difficult to determine what exactly triggered the accident on the second dive, the divers’ plan to explore beyond their limits vastly increased the likelihood of an unfavorable outcome.
Additionally, a misunderstanding of the divers’ remaining gas reserves after the second dive may have contributed to the fatal accidents. The diver’s 53 ft3 and 72 ft3 aluminum cylinders were considerably smaller than the “standard” 80 ft3 aluminum cylinders. Because SPGs only read pressure, the divers may not have realized how limited their gas supply was before starting their second dive.
Recommendations
Courses to dive overhead environments (caverns and caves) are designed to educate and train the diver amongst other things in adequate gas planning, necessary equipment configuration, and emergency procedures in this special environment.
Divers should be diligent in respecting the limitations of their training. This includes staying out of overhead environments (physical or decompression) if not sufficiently trained as well as conducting thorough pre-dive briefings that include thorough equipment and bubble checks. Gas planning should be done on every dive to ensure that adequate reserves are available for sharing gas in case of emergency. Turn pressures and minimum gas reserves should be agreed upon by all members of the team before the dive.