the OP is not talking about propane
he is asking about CNG- compressed natural gas.
our CNG tank, which is just a 'certified for cog' scuba tank, gives us about 30-40 hours of cooking.
you can check for refill site information with safgas:
SafGas CNG LPG for Boat and Yacht Gas Stoves : Fuel Locations
or Corp Brothers
CNG Dealers at Corpbrothers.com
and I would suggest you contact either for info on bahamas availability. CNG is a safer system, theoretically, than propane, which is why the insurance company would be concerned if you just jury-rigged a propane conversion. If you want to convert to propane, you probably
will have to get new stove, as conversion burner jets are very hard to find for typical marine stoves, although I have heard that readily available kits for household conversion to propane are available. Just remember, you are dealing with a substance (either one, CNG or Propane) that can go BOOM with any installation errors.
We have decided to keep the CNG for a while while in US waters. YMMV