Ex-Pro Surfer Surfs 40 Hours, Smashes Record For World's Longest Session

Former pro surfer Blake Johnston surfed 40 hours, smashing the previous record for the world's longest surf session on Friday ... and it was all for a great cause!

The Australian surfing coach entered the water during the early morning hours Thursday (around 1 AM) and surfed over 600 waves, before leaving the H20 around 5 PM, easily passing the prior record of 30 hours and 11 minutes.

Johnston didn't just shred for nearly 2 days straight for fun, he raised money to support the mental health of the youth in Australia. It's a cause near and dear to the surfer's heart ... he lost his father to suicide 10 years ago. In an effort to bring in as much as possible, Blake teamed up with the Chumpy Pullin Foundation.

Blake was able to continue surfing when the sun set thanks to the help of some spotlights. Medics, who monitored Blake's health, were also on standby in the event he needed medical assistance.

Hundreds of spectators showed up to witness the historic moment, and Johnston admitted he was "pretty cooked" after breaking the record.