I have had flat bottom, 6 degree and 10 degree bottoms on my Jon boats.
The difference between flat and 6 degrees isn't much as far as ride goes. It does help the boat turn better though.
10 degrees is pretty good in some chop in the Delta.
For a jet boat the flat bottom for rivers only has some advantages:
1) I think they do get up faster.
2) you can bring them in to shallower water which is great for getting in and out of, especially old guys in waders.
**but they ride badly in the chop on open water.
Some guides like the steering up front so they can see better for running rivers.
Some guides like a 10 degree bottom on a jet boat for fast maneuvering too.
Bill Kiene - Senior Travel Advisor
WILD ON THE FLY - Fly Fishing Adventure Travel
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2752 Marconi Ave
Sacramento, CA 95821
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Rainbow River Lodge, Iliamna, AK