Engine heat when running, diesel heat when not
So I'm a bit of a newbie to heating in a boat. I am going through a repower to either a Merc 300 HP gas I/O or 350 HP I/O and in the process I discovered the engine can provide in cabin heat (Thank you Jesus). I was in the process of having my refit guy instal a diesel heater to my gas boat, with its own smaller tank. Is there any way I can use heat off the engine, then when at anchor I can use the diesel heater basically using some common units of the system, rather than two complete seperate systems.