you can not see ANY fiberglass on the inside. It's all wood on the inside and well insulated. We found that just one of our round wick oil lamps puts out enough heat (plus our 2 bodies) to keep keep the boat comfortable. So the oil lamp in there was just a continuation of that. And we are comfortable using it over night. With the viewing door closed, very little light makes it out. Sort of like a night light.

And Ohhhhhh SOOOooo comfy!

Greg