Background: The recurring failure of survivors of accidental water immersion to self-board a life raft prompted us to quantify the requisite physical attributes for successful self-boarding for predictive purposes.
Methods: There were 24 men and 24 women (18 to 52 yr) who attempted to self-board an inflated double-tube life raft using ladder, ramp, and over-the-side (OTS) entry methods while wearing a lifejacket in warm, calm water. The OTS method was also tested under weight-bearing conditions to determine the subject's 'reserve' capacity (i.e., maximum additional load capacity).
Results: Out of the 24 men, 22 successfully boarded the life raft, as did 17 out of the 24 women, using all methods of entry, and their reserve capacities ranged from 2 to 23% of body mass. Men reported lower efforts of exertion and were faster than women when using the ladder or boarding OTS without weights. There were no gender differences in these measures for the ramp and weighted OTS methods of entry. Strength and tallness were positive attributes for boarding the life raft using the ladder and OTS methods of entry, but not when using the ramp, which was the easiest and fastest entry method to execute.
Conclusions: Men were more successful in boarding the life raft OTS (approximately 90%) compared with women (approximately 70%), but the difference was less pronounced for the ladder and ramp entry methods. The subjects' limited reserve capacities suggest that heavy layers of wet clothing and/or loss of muscle strength can easily compromise an individual's ability to self-board a life raft.