What you are looking at, are micro scratches in the gelcoat finish. To
bring the finish up to a show quality, wet sand with 1500 grit then 2000
then 3000 and then then compound and finish with foam pad using 3m
perfect-it 3000 products that you can purchase at the local auto paint and
supply company. Its a lot of work, but you will get the results you are
looking for. Here is a link that tells the process with the photos of the
products to use. The process is the same for gelcoat and paint.
http://www.shieldfinishes.com/3mfinalfinish.asp

Don't wear your self out
Bruce