I have a catalytic propane heater that runs on the small disposable bottles. It burns through a bottle in about 3-4 hours. Gets expensive real quick when temps dip into the low 50s. Other than that, it works great for mildly cool temps.

For a cruising heater, wanted something that was vented to the outside for dryness. Lived aboard in Norfolk one winter with an unvented heater. When the temp dropped much below 50 degrees, the heater created so much water that the boat was almost unlivable. Every surface in the interior was covered with a sheen of moisture and actually had to run the bilge pump because of the condensation.

When I looked into cruising heaters, dropped the Propane variety real quick because of the the pain of feeding the thing. Propane is often a PITA to get refills and carrying extra fuel for the heater isn't easy. Decided to go with a Dickenson Newport diesel heater. Added a separate 10 gallon tank that I connect to the engine to extend range under power, if needed. Extra fuel can be stored on deck in Gerry Jugs and diesel is easy and convenient to find almost anywhere there are boats, not just yachts. Thought for a brief while about getting a wood heater as my planned cruising area has tons of driftwood for fuel. The thought of dealing with the ash decided me against that.