people tend to have to leave there boats for periods to get supplies,trips to the pub or even stood on the back steering..it normaly goes "light fire leave running all winter" its never going to take off if a system has to be shut down everytime you need to leave the boat.....even if you sort all the emisions,fueling and reliability issues out.the waste oil still needs to be filtered.garages have a way of chucking rubber gloves,anti freeze,brake fluid and alsorts of other rubbish into waste oil which alters the burn and cloggs needle valves..we have been playing about with these systems for a few years now and its a mine field.yes we have a succesful garage heater and a decent water heater BUT a very big NO to a stove id want to live with on my boat..the more we learn the more issues and problems we come accross..i missed an meal out a couple of nights ago because we were playing about with a forced air system till the early hours..loss of browny points with the mrs and we didnt resolve the burn issue with the stove..if you look at a simple reflex stove and think along a similar line you wont be going far wrong..