Our long term project! After many years development we launched our custom designed SAR and Flood Rescue airboat. Airboats similar to this are extensively used by US Coastguard and SAR teams, and proved themselves in the evacuation of New Orleans during Hurricane Katrina. An airboat has no moving parts on or below the water level so can operate in 1″ of water or even dry ground. Flood water can often be too shallow for boats to operate and has lots of debris that can foul propellors.
We purchased this secondhand when it was fitted with 9 seats and have systematically replaced everything but the hull and rudders as we have rebuilt it for our purposes.