Originally Posted by steelguy
thanks for all of the responses and suggestions, seems this condensation problem is not limited to thin wall fiberglass walls. The bow deck and the gunwales are thicker with fiberglass sandwich balsa core, which I'm guessing is the reason they do not sweat. With the commercial synthetic carpet tiles, which are mildew resistant that I have been looking into, the 24"x24" squares come with a 1/4" thick black foam backing. I'm guessing that backing, along with the carpet pile will provide the thermal break needed to do the trick. This passive approach, versus dehumidifying and heating, seems worth trying. Plus, it has the advantage of offering a visually acceptable finished surface.
Forgot to mention that I have an alloy roof on my Cat which is open at the sides, and yet condensation still forms on the inside surface of the roof in the winter...
...ventilation will not stop a difference in temperature between the morning mist on top of the water, and the inside of the metal roof.