I re-checked the marks. You're right, it wasn't a discoloration. It's definitely patina.

Seriously, I don't mind seeing the darkening - I just thought that it was caused by UV and that blocking the UV would prevent it. It's either not caused by UV or it doesn't take much UV to make it occur.

But, it's definitely patina.

Ross

: The space below my hatch straps and bungies also show fairly permanent color
: differences, but like you say they are under the straps and bungies. I
: don't see this as a problem, it is just part of the natural patina an
: older boat will acquire over the years. It goes well with the scratches
: and scuff marks.