I'm surprised no one has mentioned Float Coats. I really liked them when kayaking around the Channel Islands, especially if I were doing so solo. I would wear the bottom half of a Farmer John wetsuit and load up the pockets of the float coat with flares, mirror, etc. and paddle away. On sunny days I would don a work type PFD - one that had integral pockets and load them up. I was in a situation where I was always close to shore in the event that I lost my kayak and I made sure that I had signalling gear.

If I remember correctly, my float coat was certified as a type III preserver. It did not impede my arms when paddling.