Doesn't look too bad, but Glenn's right, the gelcoat looks to be all that is cracked to me. Probably a very neglected boat left out in the open and never waxed, etc.
A LOT of sanding to get through the gel coat, then a lot of resin and glass fibers (Pull apart some mat) to get it all level again so it don't look like a washboard once you paint it. (See, I'm learning guys!).
If it's flat, yeah use a 2x4 wrapped in sandpaper (I suggest at least 18" long and use random angles) to block it out. If it isn't flat (And I've yet to find a flat surface on a boat), gonna take a lot of touch and feel. I used to just use just my hand on cars years ago on curved surfaces, then rattle can on some cheap, fast dry high gloss paint and see where I needed to smooth it some more, then circle those areas with a Sharpie. Usually took a couple hours on say a quarter panel to get it perfect.
Hope this helps, some, but nows the time to get it right. Proper prep and sanding are 98% of any paint job.
The Moo, while looks cool, is gonna get a complete, proper, redo this winter (In the same scheme, I gotta), but wasn't done right. Can still see the outline of the original striping scheme when in the garage under the fluorescent lights at certain angles. In daylight, looks perfect. I'm picky.
Ray
