We don't know, the boards constructions or the size and nature of the damage.
If it's just surface damage to fiberglass, the 2 layers of 4oz will be fine.
If it's sandwich construction, and the damage has penetrated to the core, then it gets more complicated. Some pics would be good.

Simplest repair is

Tape off area
sand and tidy up damage
mix resin with q cells to a whipped cream paste
fill hole (over fill)
-when cured-
sand to shape of board
Laminate 1-2 layers of glass cloth
sand
remove tape around area
finish coat.

WillyWind said..
Also, do you think the fiberglass will adhere to the paint if I sand the paint a little bit where the Tiki man is and lay some fiberglass? Or I should never lay fiberglass over paint at all? I always sand all the paint before glassing but wondering if sometimes we can get by with a little overlap.

No, the glass won't adhere to the paint, need to sand all of the paint fronm the damaged area. But don't sweat it too much as with that construction, the rest of the board will be delamming shortly.

Thanks, all, for the replies. Mark, I filled the deep hole (maybe over an inch?) in several stages. I mixed the glue with water and poured it in the hole, let it cure and repeat. I then sanded flush and applied a coat of epoxy with thickener (west system microfiber or Cab-o-sil) because that foam is super porous. I did this probably a year ago and today I decided to continue working on it.

My only goal is to have a water tight board to give it a try. My only foil board is 76cm and 124l (Roberts flight GT), I use it with the IQfoil foil (1000, 800, and 650 wings) and I always wondered what is like to foil with a wider dedicated foilboard. This board I'm repairing is 85 cm wide and 144l.

Does anyone know what are these "plugs"? I found several around the rail.