Moryak,
You should have used "Borat" as a screen name!
Can you explain, or better yet post some video, of the areas you are looking to run? You say your waterways have sharp turns, but the whole concept of operating an airboat is to stay out of the river channel and run the shallow marsh, unless you are dealing with rocks, snow, ice etc. If you are running deeper water (3" plus), you might as well run a mudboat system, better fuel efficiency, but less fun.
It would be best to start with an explanation and discussion of where you are really going to run this blow boat.
Here in Florida, the rivers are full of sharp turns, but I don't care, I run the marsh on the edge of the flood plain and go straight. Without you having airboat experience, your mind naturally goes to running the river like any other boat. After running an airboat for a while, you will understand that the last place you want to be is in the river, that's where boats sink.
My point is that the choice of flat bottom with turning chines vs. the round bottom hull is a function of the application. Hard chines and a flat hull do improve the ability to make sharp turns in deeper water and do help a boat fly over thick sawgrass in our parts. But when running shallow water (to ~ 4") with vegetation, the round sided hull is more forgiving as it rides over obstacles while sliding sideways. The thing to keep in mind is in shallow water, the flat cannot roll and dig the inside chine in like it can in deep water. In shallow water the hull stays flat, the chines don't work since they don't touch the water and when turning the ability of the hull to ride over obstacles is subject to the angle of the crease in the hull.
On the other hand, in deeper water, the round sides make the boat less stable off plane and ride deeper in the water. Stability is limited to the width of flat hull, before the round. In shallow water, the round sided hull can actually lean into a turn better vs. the flat hull staying flat.
