I''d try repainting it with a
paint that includes a non-skid compound. Interlux sells such an additive. There are others.
I am also in the process redoing decks. So far, I have had success with masking the area and painting with Interlux primer, then sprinkling old fashion walnut shell on primer
paint. After it sets and I brush away the excess, I painted over it with Muralo laytex
epoxy deck
paint (Sandstone color to contrast the white non non-skid areas. Great traction!
This is what I have done and it works well for me. The Interlux web site at www.yachtpaint.com has info, I believe. There are other options also. Check the sailnet store.