They do work...but you may want to build some sort of stand for it, as even the sway of the boat at anchor
could tip the whole thing over(embarrassing, mildly dangerous...and hungry-making!)
You might want to check out the small portable gas wok-rings available very cheaply at asian grocery stores.
This is a single burner (self igniting) that is about 12x12x4 inches and fairly stable and sturdy. It runs on aerosal type cans of propane and burns very hot and very effieciently. Excellent for cooking and very portable and safe.
They run about $12US plus the tins of propane.
I actually plan to take a look at modifying a system so that I can use mine either with the plug in cannister for portability or with a hose connection to a regular bbq gas bottle. They are small and nifty addition to a galley that may already have a gas or alcahol stove
. (seriously much hotter).
Another option that is used by some local racers here is to get a stainless steel kettle spot welded onto the top of a a campers stove
that plugs onto a small gas-bottle. The entire contraption is then hung off a hook form the cabin ceiling, which means it is gimbaled.Then you just turn it off, unhook it and pour the bioling water onto the instant whatever you want to fuel
the crew with. Not exactly gourmet cooking.