i do both piston and turbine airboats, my orders come from the middle east and russia where applications are different, oil fields in area that cannot be reached by boat or by truck, helicopteres too expensive, the turbine airboat is the right solution, very powerfull, the fast response of piston engines not really needed, i can carry a lot of cargo.
also for professionals in this area it is mandatory to use diesel fuel, never heard of a diesel engine airboat
The only reason you might not see my turbine boat in the US is for maintenance, few people know how to service them and are reluctant to buy them.
Yet turbines are great, i just presented my new powerboat at the Dubai Boat show , a monster of 10 tons, 54 ft, trimaran powered by 2 x 1,400HP turbines, so small that it is making my trimaran the fastest one in the world at 100mph ! , what a ride!
There is also a Sheikh here who rides a bike powered by a 150HP turbine to speed up to 250mph, i beleive Jay Leno has one too. turbines are great!
However i will sell my airboat, ducted fan and carbon fiber hull, in the US with the chevy engine.