Hi Icemanf4i,
The inflatable suspenders are a good idea. Auto-inflate type may not be good for fly fishing. They are more intended for boaters who may fall into the water. You may fall into a stream and not need your vest but it will inflate. My preference is a manual inflatable. If you put your suspenders under the vest you need to inflate them to make sure there is enough room under the vest for the suspenders to inflate fully. I don't zip up my vest over the suspenders. I just close it with a Velcro closure. you can use the mouth inflater to inflate for a test. You should inflate any inflatable devise to make sure it has no leaks. I think the Mustang Suspenders are a better choice than the SOS suspenders but they are more expensive.
One trouble you might have is the heat in your area. The suspenders or inflatable vest are hot in hot weather. The suspenders would be a better choice in the heat. A even better choice is the belt type inflatable devise. The belt would be my choice for trout fishing in hot weather. It is not the best choice in a very fast boat. They work very well for the wading fisher.
Frank
Mustang Inflatable Belt
Mustang Inflatable Vest
Stearns Inflatable Vest
