It's flex, and seeing as how the waves are always better in the morning than in the afternoon, why don't you just forget about flex and surf before school?
Let's see here:
1. Flex: wake up early go to school. Leave at around lunchtime. Surf whole afternoon (not as good waves)
2. Regular: wake up early (around 5, 5:30) get to beach by sunrise, surf for about an hour and a half (better waves) and get to school by 8:30.
That leaves 2 basic choices: Longer session, mediocre waves OR shorter session but better waves.