Porthbean beach is a small beach just a stone throw away from St. Austell. The beach is accessible for divers via a steep road, allowing you to off load all your dive kit on the beach. Parking is up the hill again on the other side of Porthpean Beach Road.
The beach is popular with canoeist, so be aware of them and ensure you use your SMB when diving. Entrance is simple, you walk backwards into the water. The majority of the area has a sandy bottom and doesn't get much deeper as 3m. The nicest part of explore are the cliff on the northern end of the beach. There can be a bit of surge taking you back and forth as you are very shallow, but nothing really dramatic.
The beach is ideal if you want to dive, but the sea is too rough for the dive boats. It allows you to dive in a very protective area. There is not much too see underwater, but it is pleasant bimble around.