Gelcoat

I have done two boats...one was a 78 Ski Tique with white gel and yellow/black lettering.  It had a few scratches and some minor spiders and we compounded and polished and the white came out well.  It is not perfect but good looking post-work.  Some folks have had  to sand too but more than likely for white, you can heavy duty compound, polish and wax and be happy.  Matching white is tough!  So I would think twice before grinding spiders and scratches unless they are not seen (on the hull bottom).  Sanding a scratch and then doing the above process gets it looking good from 5 feet.  See my thread http://www.correctcraftfan.com/forum/forum_posts.asp?TID=40614&title=new-to-me-78-tique for pics and discussion.  Your hull is prob faded but also, the white used by factory was not bright white.  It was a little off.  Others can chime in on the color.  We tried to match in some places and we had to tint the white with some yellow I recall.