CNG
Your information is correct. LPG is heavier than air. If you are using LPG the compartment housing the fuel cannister must be vented OVERBOARD. I use CNG which is considered safer because, if a leak develops, the gas will naturally vent up and out due to it being lighter that air. CNG is like the gas used to cook at home. You can buy fittings to convert from one fuel to the other. We like the convenience and "no-worry" (by comparison) of CNG. The drawbacks are few. 1. It is more expensive 2. It is not as readily available in areas outside L.I. Sound and the Chesapeake.When we are out cruising the primary cooking appliance is the LPG Bar-B-Q. I'll buy a number of fuel cannisters on sale during the winter and store them in the transom locker. Use of the oven and stove is minimal, but not at all eliminated. Therefore, our CNG lasts quite long.PJSp