Do this at your own risk - I used acetone from CVS ( not fingernail removal polish). Pour some on a paper towel and wipe the plexiglass. Then wash with water. In my case the scratches were from the jib sheet and they came off very easily. Then I sprayed it with RainX - a product in a yellow spray bottle available in an auto store. It puts a layer of wax on the plexiglass so that water runs off and it always looks good - no water mark.

(Interesting, Haro. I don't think I'd try that, but who can argue that it worked for you.)

Nevertheless, Kevin, are you seeing true scratches, i.e., that are 'cut' into the surface of the plexiglass? Or are you seeing what most of us see at some time or other, *crazing* that is not on the surface, but that occurs deep within the plexiglass? Crazing has no cure other than removal of the offending sheet and replacing with new.

Clear-to-sea is a decent product for minor scratches.It is also an awesome cleaner.

Meguiers also makes a scratch removing polish for plexiglass. I've always had good luck with their stuff.

Mike

Let us know what works best - I'm sure many will be interested.

The white MAGIC BLOCKS, (about 2" X 2" square soft squishy blocks, wet, worked pretty well to clean the windows with out use of anything but fresh clean water and a clean towel.  Wont do away with deep scratches but will take off scuff marks.  Works very well too to clean up some of the glossy gel coat that gets shoe scuff marks.  

I used this 3M polishing compound with Excellant results on ports and hatches.