The Boeing Hydrofoils went into service between Oahu, Maui, and Kona, Hawaii many years ago but met with all kinds of problems..a major one being collisions with whales. I think that the collision problem with manatees might be a major problem here.
Those hydrofoils were eventually relocated to Hong Kong where they began the HK to Macao service
Having the problem (as you stated above) with collisions with the sea life and the possibilty of disturbing the eco system while conducting business is why I had thought of the hover craft since there is no hull that sets down into the water. Yes they are noisy that is sure, now as far as the fuel mileage that is something I yet have to check into, I no that more fuel efficient motors have been developed.
Thank you so much for your imput .....everyone