Our experience is that a small dehumidifier is adequate to prevent mould. We sit it on the counter beside a basin and run a small hose into the drain from its cup. But, that is a solution for when we are not in the
boat. As several recent posts make clear,
condensation when people are breathing in a boat in winter is a real problem. In our case though during the three winters (as defined in north Florida) we spent on the boat our
heating the
interior pretty well took care of that, as well.
So, without as much information about your particular circumstance as I would like I'm inclined to say that any of the Meaco dehumidifiers will do the job, or possibly be overkill.