From the Land Bank‘s description:

Seven hundred feet of beach are preserved here at the neck of land where the Katama Bay and Edgartown Harbor wash into each other. The wash creates swift, scouring currents; swimmers will find that water becomes rather deep rather fast. The Edgartown lighthouse and the North Neck bluffs sit opposite the beach and the inlet is a parade of boats all summer long. The Martha’s Vineyard Shellfish Group leases the beach-house here and uses it as a satellite nursery, supplying shellfish spat to seed the Island towns’ ponds and lagoons.