Incident Report

2025-05-14Approximately 10 minutes into the dive, a copious amount of bubbles suddenly began spewing from the diver's right cylinder. The diver immediately shut the cylinder down, switched to their left reg and determined that the problem was coming from their right first stage. Deciding to abort the dive, the diver signaled the problem and the need to exit to the diver who had been following behind them, but was unable to communicate this to the diver in front due to the twisting and tortuous topography of the passage. The two divers safely exited the cave and were soon joined by the diver in front, who had quickly noticed their absence and turned around to search for their missing companions. At the entrance of the cave, the diver was able to use a toolkit carried by one of the others to partially disassemble their right first stage and determine that the internal o-ring in their DIN subassembly had failed and was now damaged. They replaced the o-ring, reassembled the first stage and successfully completed the dive without further issue.Carrying a tool kit and spare parts is extremely useful on dives, especially when the cave entrance is located inconveniently far from attendant vehicles. It is speculated that the o-ring failed because the DIN subassembly worked its way loose from the first stage body during prior cave trips that involved carrying the regs while rigged to cylinders out of the water between sumps. Occasionally checking this interface between dives and not just during servicing to ensure it is still tightened to the manufacturer's specified torque using a torque wrench would help to prevent this scenario in the future.