I am planning to begin living aboard, and a good heater is definitely necessary. Wood and waste veggie oil are both free options in my neck of the woods. I have been looking at the HUNTER SPACE HEATER ARCTIC (SHA). It burns kero, gasoline, jet fuel, diesel, cut veggie oil, wood, charcoal, or coal. That is some serious versatility.
I completed the installation. The unit works excellently, it is very efficient. Zero smoke. Very little thermodynamic waste out the flue. It is easy to operate and provides one excellent spot for a teapot or a frypan. I am very satisfied, I would even suggest it to any who do not care to much for aesthetics.