Older self activating life jackets had a wax type of cover to the activation unit and therefore were more likely to activate when splashed with water or if the wearer slipped and fell into a shallow part of water. Modern devices use a pressure device which has to be submerged to about a half a metre ish, before it will discharge, consequently they are less likely to discharge their gas if splashed or in fact they are soaked in water from a fall.
However the fact remains, auto life jackets are great in an environment in which the wearer falls and doesn't have to find the firing cord. However not so good in and environment in which they are in a cabin or under a boat.
For me, the answers have already been given and the chances of being caught in a cabin or under a boat are rare. Therefore Auto life jackets are our choice and are worn all the time.
Most are much of a muchness as long as you buy a recognised manufacturers make. I found the trick is to buy one that has a reasonable replacement, I have Hammar heads and they seem expensive. So why do I keep replacing them at £35 a time, well its not much if it saves a life is it?





