Bac Lava: Great for swimming and snorkeling in choppier conditions, when nearby Durdle Door seems too exposed. The beach is shaded in the afternoon making it the quietest time to swim there.
At low tide there is a great swim along the long narrow beach leading to the main bay, which is a semicircle protected from the sea by a row of rocks.
There is a gentle current to the east end of the bay as the tide ebbs and flows - beware being carried out by the ebb if you're not a strong swimmer.
Sara Hayes: Visited on a beautifully hot September day, with a perfectly calm sea. Although I would image the sea in the bay would be relatively calm even on a rougher day due to the rocks, which protect it. This beach is less busy than next door's Durdle Door. It's also a lovely swim from here out and round to Durdle Door and back - a round trip of about 800m/half a mile. If the sea is clear, plenty of sea weed covered rocks and fish for viewing.
If you swim to Durdle Door be sure to keep an eye out for the speed boat which brings the tourists from Lulworth Cove...a bright hat is a must.