Just because your surfboard got creased from stomping that massive punt, or while getting flogged during that last swell, doesn't mean it's trash. If you've got the slightest bit of DIY gumption and interest in ding repair, then here's how you can resurrect your blade to a rideable state so you can surf the remainder of your trip, have the board back in your quiver for the next swell or hawk it on craigslist.

Joe Roper's Surfboard Repair is a San Diego surfing institution and local icon. Aside from charging La Jolla's outer reefs his whole life, Roper has been fixing, restoring, salvaging and reshaping surfboards back to sea-worthiness for over 40 years. He's masterfully fixed every type of damage ever inflicted upon the sacred craft, just take a look at his Instagram for examples. When it comes to foam and fiberglass, the man's a miracle worker. And in the video above, he imparts some of his ding repair wizardry.
Tools and supplies

If you're traveling, most of the materials needed to at least repair your buckled board to a rideable condition can be found in compact ding repair kits like this one.

Hopefully there's some type of boating industry nearby if you didn't pack a ding repair kit. These types of businesses will have fiberglass and resin supplies on hand for you to buy, barter or beg to use. They might even have power and an angle grinder that they'll be willing to loan you if you're lucky.

Surfboard glassing factories or industrial surfboard supply stores are great places to get supplies if you're at home or at a location with a surfboard industry. They'll have the supplies you'll need for a reasonable price and maybe they'll even toss you some scrap cloth to use for your patch job for a few bucks or a six pack.
Checklist:

Angle Grinder
Sandpaper (100 grit and 180 grit)
Sanding block
4 oz. fiberglass cloth
6 oz. fiberglass cloth
Scissors
Resin
Catalyst
Q-cell filler (cabosil or arosil)
Surfacing agent
Tongue depressor
Disposable cup
2" Brush
Squeegee
Acetone
Rag
Masking tape
Razorblade