Keith, I think I found a pretty good compromise, which I didn't mention, as I am unsure if such an item is available elsewhere.
An Australian company produces a huge range of lifejackets, including industrial ones (for ship pilots, oil rig workers, round the world sailors etc). The one I got is called a Stormy Lite, and is different from the norm in that it has 7 pockets as well as 8 external tags for attaching equipment. In addition, the bladder inflates >inside< the vest, so the vest needs to be quite loose (eg very comfortable), as well as have thigh straps to prevent the user slipping out of the jacket. I have also added shoulder straps to wear my VHF and PLB in deployable positions.
While I appreciate the advantage of a foam-filled lifejacket in the case of the user losing consciousness, it is also possible to partially inflate a jacket to provide some permanent buoyancy for when conditions start to look dodgy. I believe that just falling out of an Island is not a huge probability, but that is just my take.http://www.stormylifejackets.com.au/
2012 Tandem Island "SIC EM"www.scenefromabove.com.au