CNG vs Propane
CNG is not available in the Bahamas. Propane is somewhat difficult but available at the major settlements. Sometimes you have to drop off your tank and pick it up later or the next day. 10lb refills cost about $15.
The issue there is that in the US your propane bottle must have an OPD valve (Overfill Prevention Device) which our government instituted to protect us from ourselves. In the Bahamas, where there is no such requirement, the OPD valves cause problems for the gas company. The Bahamian filling stations feel that they can't fill the tank enough and so bang the tanks on a rock or something to unfreeze the float and thus try to get a few more pounds into the tank. That has to be helpful?
Anyway, we used to be able to get CNG here in St Petersburg, FL but no longer. CNG on boats is a white elephant from the 1980s caused by the Cole Bros. distribution system.
I would agree that it's a good system for boats ... our Tartan 34 had the system and it cooks just as well as propane despite the BTU difference but then I've used a newer model Origo alcohol stove too and to boil a teapot full of water for my coffee in the morning, the Origo did just as well as either CNG or propane.
One other note on propane.
I have a brass fitting that allows me to refill the camper gas (1lb) bottles from a larger propane tank (10lb on my boat). It's very simple and works well. Cost was $14.95 from Harbor Freight Tools. It also works in reverse. It's a handy back up to running out of gas either for the stove or the grill. Camper gas bottles in the Bahamas cost $7 or $8 each if you can find them.
We start each season with two new bottles and end up refilling them each a couple of times. We also take some care to coat the bottles with Boeshield or similar to minimize rust.
I also have a fitting that allows me to connect a camper gas (1lb) bottle to my house system ... never had to use it but it would get my dinner to the table if we ran short one evening and our spare tank was empty too.
I just love redundant systems.