International has a granular additive to add to paint or gel coat, it's rounded so no sharp edges, I've done it to a few boats now, I apply it with a 4 inch high density roller. You mix it in the paint tray and go over the surface once, if that's not enough grip you go back over a second time straight away and it sticks a lot more grip on, it's very good and much cheaper than tape

Jeff Southall
Current boats
Nacra 5.8 1703 Animal Scanning Services
Nacra 5.8 1667 Ram Raider
Nacra 18 Square
Arrow 1576