just came across this on line, mercury racing off fond du lac, are teaming up with a turbine company to possibly produce an allison 250 turbine outboard, mating a turbine onto a mercury race leg and gearbox
As a response to military requirements, MTT designed and built the first turbine-powered outboard motor. The MTT Turbine Outboard was demonstrated to the US Military in an effort to assist them in fulfilling their mandate that all equipment aboard military ships must transition from gasoline (a more volatile fuel than diesel). The outboard was used to power a landing craft carrying a S.E.A.L. Delivery Vessel (pictured above) and other vehicles, performing with amazing results.