Tips needed for removing black marks caused by boat cover

[Erie660]

I have some marks on the gel coat created from trailering the boat with the cover on. It probably was caused from flapping in the wind. The cover is black so now I have a few black spots on the boat. It suppose to be a trailerable cover but not if I'm going to get these marks from it. What's the best way to remove these spots? Thanks

[SwatDawg]

Vinagar and water, simple green, any of that should get it... Next time if your gonna trailer with the cover, put some seran-wrap around the boat where the cover sits

[DOUGMCGEEFTD]

get you a little 3m perfect it compound. littel dab on a rag and wipe it in good by hand on a small area. you should see the stains or streaks go away!