Surface temperature with black gelcoat deck

I have a boat here (open Poweboat) that exhibits gelcoat problems; it's lying south and has a black gel coat!!
And a black boat cover as well, does anybody know what kind of temperatures may be measured on black deck or underneath a black boat cover?

 

High.. But you could get a thermometer (besides painting)

 

I'm not sure the actual temperature will matter, because it will be too hot.

 

What does "lying south" mean ? If you want to know what the temperature is accurately, you can buy some melt-sticks.

 

South means south of Germany, i am actually looking for a long term high reading, lets say over over a summer, the highest temperature, I was hoping for scientific published work

 

With black plan for about 185F, white will be around 145F.

Some people claim to see higher temps, but when I test surfaces normally I’m in this range.

There are locations in some regions where the ambient temps can shoot this up higher though.

 

This is very location specific, what you see as a peak reading in one region could be low or high for another region. What someone else records, whether in a scientific report or not, is only relevant to that location.

We test gel coats in real time long term tests in Arizona, the days are long and the ambient temps may reach almost 120F. This will be far different than what most parts of the world will experience.

 

What problems are you seeing in the gel coat.

Also, putting a cover over it, even a black one, will keep the gel coat cooler than if it was in direct sunlight.

 

My black RIB tubes were about 170F at noon here in South Carolina in July.