The book that spawned the question and now free to read here :Fishing Smarter for Trout
Wearing a belt round waders helps stop water running into your waders when you first fall in a river. If you do get washed away after you fall in, the air trapped in the waders will greatly help to keep you afloat. Then you can concentrate on getting and keeping your feet facing downstream, and moving yourself as quickly as possible to shore by moving across the flow; never try to go up against the flow.
Thanks for your reply, it created quite a good discussion and questions at work regarding the use of a belt with waders for safety reasons. We agree with your idea of using a belt if one is wearing PVC type waders. But if the fisherman were wearing the Neoprene type, would he still need to use a belt? I was under the impression that these Neoprene waders float no matter what, possibly a wrong assumption.
Your comments about PVC or Gortex type waders are spot on - you should always wear a belt with these waders. In fact the better quality waders of this type come with a belt built in.
Neoprene does float, but its ability to support the body depends on the amount of clothes the dunkee is wearing. In any event it is not the floatation that is usually the most pressing issue - but safety from getting knocked about on rocks, trees, etc. Waders full of water make movement in the water very difficult indeed.
It is imperative that you try and keep your feet pointing downstream, to avoid being hit on the head on rocks, tree trunks, etc. Anything that hinders staying feet first is not good.
Secondly when you get back to the shallows trying to climb out of the river with waders full of water is very difficult - especially and potentially dangerously true if you are faced with a steep bank. You can minimise all these problems by wearing a belt.
My first trout fishing book Fishing Smarter for Trout is
now up on this site and free to read. Includes regular updates and new stuff.