Hi BBarn
I was thinking of a reverse inlet too, my freind Bob Patterson has a Allison powered Unlimited hydro and when they started to run the turbines the salt water in Mission Bay it really messed up the engines.
Bob told me what they did to solve the problem.
As i recall the turbine guys built intake scoops with air diverters inside the scoop to keep the salt water out and air in , maybe a style like that for the turbo intake where the salt sticks to some panels and lets the air in.
Don