If you are only flying over water for a couple of channel crossings every summer I wouldn't worry about investing in anything else than a life west and a PLB. I'm a firm believer in mathematical statistics
That's reasonable, although my approach is to forget the life jacket and carry a raft 100% of the time; along with a bag of other emergency stuff it occupies the 4th seat.
Crossing the channel one would try to ditch next to a boat but one would be dead pretty fast just wearing a jacket.
I don't know if the survival stats support this view. Those who died aren't talking (and the bodies/aircraft are not always recovered) and too few people carry a raft to contribute useful data.
It seems that most people that go down have run out of fuel. Occassionally, I bet, it happens because they are leaving the UK with nearly empty tanks so they can buy cheap fuel in Jersey, which is daft because they would have got a similar benefit by leaving the UK with full tanks and claiming the duty drawback. Maybe some are in clubs which make the drawback benefit difficult, and there is the other side to that too which is that if you let one member pocket the whole drawback on fuel
not wholly purchased by him then you will get members taking advantage of this and repeatedly flying s. coast to Le Touquet and getting free fuel.