Three Mile Harbor is not three miles long nor three miles wide or deep. It gets its name because the harbor is three miles from the village of East Hampton. It gets its fame from its great beauty. The harbor is mainly used by recreational boaters and is a favorite destination for summer cruises.
There is a town owned commercial dock at the northern end of the harbor with a free pump out station and the Trustees provide a free pump out boat. There are numerous private marina slips and rental moorings available. The harbor is over 1000 acres in size with a large, Annual Trustee Permit Required, mooring area and free anchoring areas.
The Trustees are involved in numerous efforts and projects to maintain and improve water quality. Town residential shellfishing licenses are required for shellfishing.