The discussion of Kenyon stoves (which I hate) got me thinking about
what I really need to heat on my boat. By myself, the answer is
"Coffee" and nothing else. For breakfast, I eat a pop-tart or two and
lunch is cold sandwiches. Hopefully I am back in a port to get a hot
meal for dinner. However, on a longer passage, I do need to be able
to heat my coffee or maybe even water for oatmeal.
On such a longer trip on a small sailboat, electrical heating of water
is impractical and every stove I have ever seen makes a flame that is
potentially dangerous. Why not heat without flame?
I hesitate to post some ideas since a few may be patentable but I will
post this one. So......Useless idea #3744

Catalytic immersible water heating for food preparation.

Pass a hot hydrocarbon gas over a hot platinum coated grid and it will
decompose with the release of heat. This is how the old Coleman
catalytic heaters worked. In many cases, the grid is exposed and can
cause fire but I envision an enclosed system using a fuel such as
propane or even alchohol stove fuel.
This device would be in the shape of an elongated asterix for maximum
surface area with minimal cavities for easy cleaning. Fuel would pass
down its axis to the bottom and then back up through the arms (points)
of the asterix where it would be catalytically decomposed. The
gaseaous products would come out the top. The case of copper would be
in contact with the food or water. Simply place the heating element in
a pot of water and allow the water to boil. It could have a valve
made from that shape memory alloy that would not allow it to reach too
high a temperature.
The catalyst would have to be initially heated with electricity from
the boat 12V supply although some sort of exothermic chemical heating
would also be good. Initial electrical heating requirements
(analogous to priming an alchohol stove) should be fairly low as once
the reaction gets going it is self heating.
To avoid any dangerous hydrocarbon fuels, it may even be possible to
run this type of heater with H2O2 which is fairly cheap and relatively
safe. It decomposes into water and O2 with release of a lot of
heat.(Got this idea from thinking about hybrid rocket engines).

Well I don't know anything about anything but this seems like a good idea.
I've been waiting for someone more knowlegdable than I to comment but so far
nada.

Like you, my big thing is coffee or tea in the morning. It would be nice to
get up, get this thing going and then go do "morning stuff" and come back to
a boiling pot of water. All silent and safe -- without firing up a generator
or dealing with combustables.

Perfect for an at-anchor morning.

Well I don't know anything about anything but this seems like a good idea.
I've been waiting for someone more knowlegdable than I to comment but so far
nada.

Like you, my big thing is coffee or tea in the morning. It would be nice to
get up, get this thing going and then go do "morning stuff" and come back to
a boiling pot of water. All silent and safe -- without firing up a generator
or dealing with combustables.

Perfect for an at-anchor morning.