Re: gas vs diesel
I'l explain why I stated they require more maintenance. If the op is going to be travelling frequently from West Palm Beach to the Bimini Islands then the diesel power is the perfect choice. Fuel economy and that is how diesels like to be run. However, if like a lot of boaters, the op only makes say one trip per year to Bimini and then just putts around the rest of the time, then diesels are a poor choice.
Diesel engines should not be run at low speeds for either long or short periods, and then shut down. The problem is that they build up carbon in the cylinders at low speeds; they need to be run, long and hard to burn out that carbon after slow speed running. If not, then carbon builds up in the ring grooves of the pistons and will eventually cause the rings to stick. To prevent this, very frequent oil changes are needed.