The RH side of your "crack" appears to have either wood or glass fibers crushed at
This indicates some sort of structural damage to the skin (shell if you prefer) of
Depending on where on your board this damage is (I could not tell from the photo) I agree with Ola.
Some sort of "filled" or thickened epoxy should seal the damage and allow you to fair in
the damaged area to the surrounding undamaged area.
Fortunately, it's in the white painted area, so after you get it all sealed and faired, a
bit of masking off the surrounding area, and quick coat of the appropriate shade of white epoxy enamel (spray can is OK here) and your board will look nearly new.
Hope this helps,