1. Fine Steele Wool. I rub surface, then clean with denatured alcohol three times.
Surfboards use a wax in the last coat. You need to remove that substance, so rub hard and clean well.
2. Use acrylic paint or water based markers. Acrylic dries hard as rock and is friendly indoors/enviroment.
3. Epoxy Spray Paint Clear Matte finish on top. This stuff is nasty so use out side and with a mask. 12" away, spray light coats with a 1000 grit light dry sand in between coats. Use 5 coats with sanding between each.
4. After last coat, use a 1200 grit wet sand. Use water and slide lightly. Car wax on top for some shine!