So the guy is sitting on his board. He gets attacked by a Great White, and hops off of his board, and shoves the plank at the shark, which takes two bites at it.
The shark goes away. The guy gets back on his board, and rides it back to shore.
They close the beach.
30 minutes later, the SAME GUY shows up, with a replacement board in hand, wanting to surf.
Dang.