Last fall when I pulled the boat for the season I planned on completely redoing the bottom. I had it blasted to gel coat but weather was not on my side and had to let it sit all winter. Finally had a window of opportunity to finish the job. there were a few patches of blisters that had to be filled with Interlux watertight. Based on their locations and that they were in consistent patches I assume they were just flaws from the factory. next was multiple coats of Interlux 2000 barrier coat. I switched colors from grey to white between coats. Interestingly, the white was much more difficult to work with and did not spread nearly as far as the grey. Had to use almost twice the white per coat compared to grey. finished it off with 320 grit sand paper and spraying 4-5 coats of Interlux VC-17. Hindsight I would have done one more coat of barrier coat and sanded more first. Turned out smooth but I would have liked a bit smoother. A ton of work but in the end very happy with the final product. This is my third time doing this project but bigger boat everytime. I can see why the yards charge so much, especially the older I get!