After attending a Sea Survival course in Falmouth I got some very good advice from the local RNLI Sea Safety officer.
This was in the form of a 12 page guide from "Sailing today" compiled by the Tim Bartlett.
Considerations such as additional buoyancy when wearing foul weather gear, spray hood, auto inflation, crouch straps etc were taken into account
In the interest of safety I am repeating the conclusion on testing 30 lifejackets, though I might get told off
"We think there is real cause for concern whether a 150N lifejacket are really adequate for use with foul weather clothing. Amid this gloomy picture, though, there are a few bright spots; the Plastimo's Cruiser 150 is one of them, its light weight very comfortable jacket at a sensible price making it a good basic buy, though narrowly beaten to our budget buy award by the Parmaris lite.
For not much more money Aladdinís Cave Ocean Passage Plus is stunning value, if money is no object Crewsaver Crewfit Plus is a very conventional top of the range jacket, while the SeaSafe Sea Explorer shows what can be achieved if you treat the EN standard as a guideline rather than as gospel. An honourable mention though has to go to Viking, My own personal pick would be the rather industrial looking Viking 1 SOLAS, itís not hugely expensive but itís got enough extra buoyancy to make all the difference between floating face down and face up"
I went for the Crewsaver Crewfit Plus buts itís rather pricy, however I hope that it will last for some time and I donít think you can put a price on safety.
Out of 25 automatic lifejackets two failed to inflate automaticlly, they did say that given most manufactures buy their trigger mechanisms from the same suppliers, it wouldnt be fair to name names.