The Praia Grande beach is always crowded, no matter it is high season, or not. If you like crowded beaches, this is your place. But, if you prefer more privacy, there are several beaches options in Ubatuba.
If you dont like a very crowded beach, then dont come here. Its high season and there is a bunch of people. I enjoyed my time at this beach. It is clean and has a lot of kioks. Also, there are a lot of options: restaurants, food trucks, ice cream and even a super market if you want to buy...
I just passed by this beach without stopping by. The reason was that it was too crowded and there seemed not an inch of space available to get seated and relax on the beach. It's better to miss this beach and go over to some nearby beaches which are not too crowded.
That is a nice beach in Ubatuba, however you should be prepared for being with a plenty of another tourists. For taking rest is not the best option, but this is one of the most famous beaches of Ubatuba. Eat a pastel too and enjoy the best spare time activities of Brazilians.