The interesting thing about the 50-50-50 "rules" is that someone just made them up out of thin air. There's absolutely no research to support any of them.
- Moulton Avery
Four Popular Versions:
- A paddler has 5 minutes to swim 50 yards in 50 degree water and has 50/50 chance of surviving the attempt.
- You have a 50-50 chance to swim 50 yards in water at 50 degrees.
- A 50 year old person has a 50-50 chance of surviving 50 minutes in 50 degree water.
- If someone is in 50 °F (10 °C) water for 50 minutes, he/she has a 50 percent better chance of survival if wearing a life jacket.
Golden & Tipton suggest that 50-50-50 rules got their start when someone misinterpreted the 50% "marginal zone" survival curve published by Barnett in 1962.
[The 50% Survival Curve] has been mistakenly taken to represent the time at which an individual would have a 50-50 chance of survival rather than the survival time of 50% of individuals. Furthermore, people often forget that this time theoretically exceeds the survival time of 50% of the individuals. --Golden & Tipton - Essentials of Sea Survival