The marine environment is harsh on metal, especially in saltwater areas, and standard steel propane tanks used for cook stoves (and now for propane-powered outboard motors) can rust or corrode, increasing the risk for a propane leak or nasty rust stains. Boaters now can choose, however, to use a nonrusting, noncorrosive fiberglass propane tank instead, which offers additional benefits such as lighter weight and the ability to see the level of propane inside the tank. Read the review of the Lite Cylinder fiberglass propane tank to see if this one is right for you.

Comments
My choice is small propane camp canisters rather than full 20lb propane bottles.
I’ve got an alcohol stove and the flame is dangerously difficult to see.
However, I’m neither a live aboard or a long range cruiser, so my choice may not be suitable for everyone.
Keep in mind that there are numerous standards for propane tanks in the world. Many of the countries appear to set standards which have one business oriented goal in mind…you have to pay a costly tank inspection fee, or purchase new local tanks.
Just one example: New Zealand, the propane and diving tank inspection fee can be as high as $85 USD per tank. All non-New Zealand tanks must be inspected prior to being filled in New Zealand. And, New Zealand standards claim that fiberglass tanks are dangerous and cannot be filled under any circumstances.