Blake Lively plays a surfer in the 2016 shark attack movie The Shallows, but does she really surf in the movie? ... That happened. I wasn't supposed to crack my face underwater.

PIC: Blake Lively Hides Baby Bump in Gorgeous Cape Gown at the Met Gala "Doing the underwater sequences, I'm in 4.5-foot waves," she shares, describing some of her toughest days on set.

RELATED VIDEO: Blake Lively Calls Out Post-Baby Body Shamers “That movie was an athletic event as much as it was an acting job because they didn’t hire a stunt double until the last two weeks ...