Effects of Delays at Depth on Diver Inspired Oxygen Partial Pressures in Simulated Lockouts Using the MK 25 MOD 2 UBA

摘要

Divers using the MK25 provided data on partial pressures of oxygen (PO2) during deep lockout simulations at 60 feet of seawater (fsw), simulations in which delays of 1, 10, and 30 min at depth were manipulated before ascent to 15 fsw. Divers assumed a vertical orientation and maintained a restful state in euthermic water conditions throughout the procedure. Eighty-one of 88 dives were completed without violating PO2 safety criteria. Two dives in the one- minute delay condition (n = 25) and three dives in the 10 min delay condition (n = 35) resulted in low PO2 (less than or equal 0.16 atmospheres absolute ATA), and two dives in the 30 min delay condition (n = 28) resulted in high PO2 (greater than or equal 1.70 ATA for more than 10 min). Binary confidence limits for violating PO2 safety criteria were between 0.003 and 0.320.