anybody do any gelcoat/fiberglass repair

I was acid washing the build up off my hull yesterday and came across a spot where it looks like a rock took out a small chunk . I don't know how it happend, I haven't hit anything, but I need to fix it. it is abou 2 inches long and 1/4" wide, I can post a pic if it would help, but the hard thing is that it is on a corner of one of the strakes. Any help is greatly appreciated

I used these guys with good results! http://www.spectrumcolor.com/
They have a kit that runs around $20 shipped, easy to use, and matched exactly!