Immersion suits are always a compromise. A suit that will keep you alive in cold water will be too bulky to allow convenient operation of the aircraft. Having spent quite a bit of time in the back of oilfield helicopters, I wouldn’t want to do more than be a PAX when clad in the usual North Sea neoprene suit.
I used to wear an immersion suit for longer (UK to Holland via the Belgian coast) GA trips, but now tend to do the shorter Dover – Cap Griz Nez crossings so don’t bother. The experts on the subject are those folk who ferry light GA aircraft across oceans.
A couple of points that have come up over the years: An immersion suit is useless unless it is sealed, so it really needs to be closed up for the whole trip. When you put a suit on and close it up, you need to ‘burp’ it, i.e. squeeze all the extra air out of it. If you don’t you could be trapped in a sinking aircraft by the buoyancy of the air trapped in the suit. It may be worth your while doing a Dunker (
underwater escape) course at one of the training providers. They may be able to point you in the direction of the best suit for your type of aircraft / flying.
Safe Flying, stay dry.
WKW