Jetboil Flash Java Kit($99, jetboil.com)
Test Impressions: We bought this for camping, but all our friends show up at the dock with coffee cups in the morning, so we thought...why not for a boat? The unit is about the size of a quart jug and takes up little space. It’s strictly for above-deck use when powered with carbon monoxide-producing butane.
Upsides: It’s as simple as heating water with coffee grounds (or pouring in hot water) in the insulated tankard, letting it sit for three minutes and using the French-style press. * The results are better than instant coffee, and nearly as fast. * It’s lightweight, portable, easy to stow.
Downsides: If you run out of butane, you have cold coffee. * There are a couple small parts that could go MIA.
Recommendation: Carry hot water in a Thermos and use that for a quicker, butane-free brew.