quieter beach breaks in south west portugal

[Bella2]

I'm going on holiday with some friends to Portugal in August. I've surfed a bit (still learning though!) and the others are beginners. We're staying about 10min drive from Arrifana beach, but can anyone tell me other quieter beaches along the west coast in the southern part of Portugal? I'm guessing Arrifana will be pretty busy, and I don't like surfing when it's busy at all.

Thanks