I don't know whether you will want to do this or not, but I followed Vaclav's method with the magic marker and it worked great for getting the ripples and low areas out.

Put on one more skim coat of epoxy. Let it cure for a day or two, then take a permanent magic marker and draw a grid over the whole boat. The idea is to cover as much of the surface as you can with the marker, then wet sand off the marks. I used 180, You'll be amazed at how much sanding is needed to get all the marks off. Once you've gone over the boat, wash off the dust and such with a wet cloth and let it dry. When it's dry you should see almost no shiny spots(low areas). If you see little shiny spots all over the boat, then it's back to the marker again. I found after 2 wet sandings with the marker, I had an almost perfect surface. I didn't find any unpleasant surprises when I varnished. The one thing to be careful of is going through the fabric with over agressive sanding. The boat is matte until you put the varnish on. You won't believe just how beautiful it looks after a coat of varnish. All the prep will be worth it. Hope this helps.

If you go to the one ocean site you can find his technique.

: OK, I've got the deck glassed. After the wet-out I put on two fill coats,
: then sanded, then put on a third fill coat. I've been over this coat with
: 150 sandpaper, then 220. At this point I've still got a few very small
: ripples in the deck, but in others I afraid of going through the glass.
: Do I have to do another fill coat? Do I have to sand more? Or is this
: close enough? Am I supposed to end up with a glossy finish, or will that
: happen later when the varnish is applied?

: Chris