Use NOAA Chart 13209.
Lake Montauk is approached form the north via Long Island Sound. From the sound, red and white Morse (A) buoy M serves as the lighted primary mark into Lake Montauk. Once you have cleared red and white Morse (A) buoy M, chart a course south toward flashing green 1 and flashing red 2, which mark the east and west breakwaters to the inlet, respectively. Depths in the inlet are at least 10 feet, and usually deeper, but do take into account the strong current here.
The marinas are scattered primarily around Star Island and to the west wide of the Harbor. The town of Montauk is relatively close by and there are limited opportunities for provisioning.
Located on the eastern tip of long Island about 20 miles southwest of Block Island and 50 miles east of New Haven, Lake Montauk is the easternmost navigable harbor on Long Island and is very popular with recreational fisherman who venture out to Point Montauk to enjoy one of the finest bluefish and striped bass fisheries on the planet.
Inside the Lake Montauk Inlet, boaters enjoy 15 excellent marinas, an extensive anchorage and relatively good depths that range form five to eight feet. Of the 15 marinas in Lake Montauk, 10 of them accept transient guests at their slips, and many also offer haul-out and repair service. A large anchorage is located behind Star Island with decent holding in eight-foot depths.