geez does that ever look familiar...

That looks almost exactly like the deck of my Triton.... I do think its chipping gelcoat. I'm stoically ignoring it right now, but eventually I guess I'll have to grind it all down and fair the decks out as best I can... Then I'll go with paint. Either Brightsides or Awlgrip for the non-non-skid parts of the decks, and Brightsides with grit for the non-skid. Personally, I don't like the applied nonskid stuff (I assume you were talking about Treadmaster, or similar). I was just recently on a brandy-new Tayana 49 (sheesh, what a reeeee-diculously huge boat!) and I was struck by how TALL the Treadmaster stuff is. Its almost like you could trip on it if you aren't careful....

bottom: We (well, mostly Heather....) just stripped and barrier coated our boat's bottom. We had what must have been at least 10 years worth of build up. In some areas though, it was flaked off, right down to the gelcoat. We used several techniques: Putty knife removed large areas easily where the paint was loosly adhered. Flaked right off with little effort. Sanding was marginally effective. We also used this whacky tool which we got on loan from a boatyard which works sort of like a cross between an orbital sander and a power planer. This thing did an incredible job of chipping the majority of the well-adhered paint from the bottom, with virtually no damage to the gel coat. Then we used peel-away on all the concave areas, like the turn of the bilge. This stuff worked well for us, but be careful! It's caustic. Heather got some burns on her arms from the stuff where it got between her gloves and her tyvek suit. Bleah. Any way you cut it, getting the paint off the bottom is a miserable job! We went to a multiseason copolymer ablative, in the hopes that we will never have to try to get the stuff off again (at least not off of this boat!!!)