Order a 3 qt kit of the regular epoxy from RAKA. marine epoxies. buy a few rolls of blue tape. Find a bag or bucket of sand. Screen sand through a kitchen strainer. Poke holes onto a coffee can lid with a hot Ice pick. put sand in coffee can and make sure it shakes out nicely like a coarse salt shaker. Coat your entire floor with the epoxy and let it cure for a day or two, three days is best. Was and sand the epoxy with 150 or so orbital sander and wash again. Tape of the pattern you want and paint the areas inside the paint with fresh epoxy. Spread the sand evenly. pull the tape up pulling towards the inside. Let dry 2-3 days. Sweep off the excess sand. Lightly sand to dull pointedness of the sand Blow off with an air hose and paint with Pettit EZ-Poxy, Sandtone or Hateras Off-white. Wala !!! permanent non-skid. I did this to the entire deck on my 1959 Pearson Triton 28' sailboat. People couldn't believe it wasn't mold in , much less that I had done the job myself.
OR CHEAT AND DO IT WITH PRE-MIXED NONSKID.
Both methods outlined below:
If you need help getting going let me know.