i have the stuff, used it on my gutters to seal holes/cracks, worked good. by no means would i use this on a surfboard. just do it the right way.
grab a few of those Elephant Seal's for emergency's, they are basically thick stickers that you apply say mid sesh, until you can get to fixing the board post sesh. i have a few in my jeep difference sizes. one ding was so small and not affecting anything, i just left it on for months and it did the job.