Wood stoves are an option, but lets be realistic for a moment. Wood stoves are popular in houses and campers, which are near land and trees where wood is found. On a boat, you are floating and all the trees are far away from you!
Any wood you gather now needs to be brought back to the boat and stored somewhere! Where are you going to put all of this wood and keep it dry until you burn it?
You might think that driftwood would be an excellent source of wood for the stove, but the problem is the wood is pickled with salt. This salt will escape while buring and combine with the high heat to rust out the inside of your stove in a very short amount of time.
Wood stoves may sound cool at first, and will get the job done, but there is a serious logistical problem in getting the wood needed to the stove so that you can cook on it while cruising.
If you liveaboard in a marina, this might not be a problem as you have ready access to land and all of its amenities, giving you the ability to find and store wood for your stove.