White top is the only way. Made a huge difference just cleaning and repainting the roof when we got our boat. I can’t imagine what it must be like to have a dark topped boat in this weather!

We have a couple of largish panels towards the stern (above our bedroom). I’d say it keeps the heat off somewhat. We got a deal on bifacial panels, so perhaps this summer when it gets really hot we’ll put some foil down on the roof with the double win of reflecting heat and maybe adding a few more watts to our solar input. Not that we’d need them on the hottest days of course… Although a small A/C unit is probably within our power budget for those days now I think of it!

Ours is very much in need of a paint job. When we painted the roof, we sanded back and fertan’d some rust spots on the side, with the good intention of painting the sides later. That was a couple of years back, poor thing! Maybe this year.