"Keith" wrote in message ...
I guess your boat is trailerable?

Nope.

What kind of lights are you talking about,
navigation, courtesy, etc.?

See subject title.

If this appears no matter what, you might be
seeing "blooming" where additives in vinyl plastics come to the surface. I
kinda doubt the lenses are made of PVC though, although that's all I can
imagine. UV degradation wouldn't polish off, so you've got some sort of
contamination on the surface.

Whatever it is bonds to the surface as if it were part of it & must be
abrasively polished off.

Try spraying with a little Pam or silicone
spray after you clean them next time.

I have done this in the past (other more suitable product - silicone
sprays are awful to get on anything one cares about, especially where
long-term visual clarity is an issue, are impossible to remove from
plastics, and often cause degradation themselves; I would like to see
people who put them on things they sell mildly tortured; Pam is
vegoilarrgghh).