a minority viewpoint - CNG!
Been there . . . done that . . . argued pro's and con's . . . have used pressure and non-pressure alcohol, propane, etc. . . . what I had NOT experienced was CNG . . . and for a variety of reasons (mainly safety) I finally went with CNG and I am a very happy camper with it. I am told that in the past 40 years, there has not been one reported explosion caused by CNG on small boats. CNG received a bad "rap" way back when bottled gases were first being introduced to small boats. The propane vs CNG war was fierce and a lot of money was spent in the sales, insurance, and regulatory arenas. The propane lobby was very active, and, frankly, won the day by proposing that CNG was "just as dangerous" as propane. Well, it is just plain not true. A CNG system does NOT require an airtight box with an above water escape drain - CNG gas floats up, not down. The tank regulator puts out pressure at about 1/4 lbs per sq. inch (yes, please read one quarter of one pound) and this low pressure eliminates the need for a high pressure hose or double clamping on the hose that is used. In fact, some installations are made on boats with the tank set into a space inside the main cabin and it is accepted by insurers. So - what's the reason it is not "as popular" ? - well, the distribution availability on the coasts is somewhat sparse (for example in distribuitorlists 9 places in MASS, 3 in CONN., 4 in New York, 10 in Maryland, etc.) so, I researched and found that filled tanks can be shipped by FedEx - and I bought two tanks and keep the spare on board . . . . the stove operates the same way as a propane stove does - virtually the same btu output . . . almost all propane stoves offer conversion kits to convert from propane to CNG (and that can be reversed if you don't like it) . . . the tanks hold about the same amount of heating capacity as a propane system tank. Plenty of heating capacity while the spare is being sent by FedEx to refill. Extended travel in the Caribbean and transoceanic voyages would run into a supply problem - so that is a clear argument against CNG for some. Shorter trips - say two or three months or less - would be fine. The marine CNG system is a bit more expensive at the outset - but an exploded boat and/or airtight box and overboard discharge drain and electric solenoid safety switches and wear and tear in the worry department are not acceptable compared to the extra bucks as I see it. I am NOT connected in any way with a distributor - these comments come from my experience and research. When I have shown my installation to others, folks tell me they are positively surprised and wished they had looked at this option more carefully before going propane.
