I have dinged the rails of every surfboard I've ever owned. Generally, I crack the rails when I make stupid mistakes in the parking lot, or my driveway, though I understand some folks actually bump into things in the water. For small bumps and bruises, I keep a tube of sun curing resin around.
Repairs to your rails (the edges of the board that cut into the water) are not difficult at all! Simply clean up the cracked spot, sand it down a bit to give the resin something to adhere to, and squirt out a glob. Use some plastic wrap to mold the resin, and hold it in place, while the board cures in the sun.
Of course you can also put a plastic bumper sticker over the crack and hope it holds. I've done that too.
Be certain you know if your board is polyester or epoxy! Using the wrong resin will destroy your board, as the two do not react well. Most manufacturers will label the boards, so check the stickers and logo information under the glass.
When chunks are missing from your board, or you really gouge into the foam, there are putties and other fillers you can use, which you then cover with the correct resin. Even more sanding is involved!
I like these SolaRez kits as they come with some sand paper, which is never there when you need it.
Solarez UV Cure Epoxy Ding Resin – SUP Paddleboard & Surfboard Repair Kit via Amazon
Solarez UV Cure Polyester Ding Resin – Surfboard Repair Kit (2 Oz) via Amazon
