Sounds like an interesting experience Daniel..... probably not something to try on a regular basis
I had wondered about the requirement of footstraps after nearly being thrown out of my boat earlier on this summer whilst speed trialling my stainless prop - hit a wave doing just over 40 knots and came down hard on the port hand side. I slowed down after that and came in after that little fright
Since then, I generally take a 'Standard' portable VHF radio out with me, and put the hand strap through the lifejacket coupling at the front so it shouldn't ever part my company. Apparently, this radio is intriniscally safe, and also completely waterproof - don't know cost of it mind you since it's a company radio. The battery lasts an age, and you can swap the fixed battery with a set of something like 6 x standard AA batteries if required. It even came with a charger for a cigarette lighter socket too, which although I haven't tried it yet, should work fine on the boat.
Just out of interest, I wonder if many people 'service' their lifejackets annually? - I only say that, since our company lifejackets go in annually to cosalt for service and to check they're in proper working order. I assume the same should be applied to standard leisure user lifejackets (the same type) too?... I've seen a couple go off on friends now, and they've been almost completely unable to turn their head or even try and look down to find out where to deflate the thing from.