Yes the Solaire or other "infared type" grills are an advantage. In the marine enviroment 316 stainless will give you a much longer service life.
Charcoal ashes are a real problem and are slow to start. I wouldn't want to have to deal wth the mess.
Propane or cooking gas is the way to go. Have you seen the new fiberglass propane tanks? Lightweight, and you can see the amount of fuel in the tank. Ever wonder if your getting a full refill, or how much is left in the tank? They are great.
I treat the exterior of the metal valve/handle and regulator with CorrosionX and they have served us well.