A lot of anglers don't want to wear life jackets because they are too bulky...or just because it's a macho thing. Check out www.mustangsurvival.com
Mustang Survival makes a life jacket called the air force which is a fanny pack. It just fits around your waist. If you fall in, pull the inflater and instant life jacket.
A life saver and you can still look cool (well, some of us anyway).
Pokey