It was a great anchorage -- clean water, nice place to swim, hang-out, take a dingy or launch ride into Edgartown.
The first time we went in there in 2003, we followed Walter Cronkite's big old boat in and anchored a few hundred yards away. You can see the swirling sands' patterns especially well on the Google Earth ("Katama Bay, MA").
Also, you can get a sense of the MENEMSA POND entrance on Google Earth.