There is an adaptor
sold by Trident
Marine which makes conversion to the Gaz cylinders dead simple; it's referenced in the link to the article I wrote some time back (see above).
One issue with Talbot's suggestion is that shallow threaded fitting on the side of the manual valve. I don't like the looks of it and would prefer something designed to carry LPG.
I keep hearing comments that using Gaz containers is more expensive than other options but I doubt in reality that's true for a
boat on the move and actually cruising. Once you dip down to France (from N Europe), the standard 3 kg Gaz bottle costs about 8.5 Euros/$10 USD. The bottles are available almost everywhere, and surely one's time is worth something. We cook almost exclusively onboard and the 3 kg bottle lasts us 4 weeks; that's about $2 USD/week out of our
budget. We carry a decanting hose (and have used it) and we've occasionally tracked down the rare
hardware store or filling station that will fill a U.S. tank...but this rarely seems in the end worthwhile.
I would recommend a
storage box (or boxes) designed for LPG bottles which can accommodate two bottles. That way, you can leave one North American bottle, charged, in the box long-term and you only need to put a deposit down on one Gaz bottle. Use every bit of the LPG in the Gaz bottle (invert it for the last 20 mins of
cooking...), switch to the NA bottle for the balance of that meal's
cooking, and then do an exchange at the nearby grocery/hardware/etc. store. Given some of the logistics puzzles cruisers must solve (mail, importing something without paying a fortune,
laundry in the land of few laundromats, crowded
marinas right when you need a major provisioning), this puzzles seems delightfully simple to solve.
Jack