Nantucket Harbor offers an excellent and well protected harbor with some of the finest marinas on the U.S. East Coast. Every year, thousands of boaters flock to Nantucket to experience the history and wildness of the island while mooring in the harbor or tying off at one of the town's many marinas. The town of Nantucket and Nantucket Harbor are located 20 miles east of Marthas Vineyard and 25 miles south of Cape Cods South Shore.
The image above is a view to from the north looking south over the entrance to Nantucket Harbor at the outer breakwaters. Nantucket itself can be seen in the upper-right-hand corner of the image, while Brant Point can be seen working right to left (west to east) into the harbor. Off to the left (east) is Coatue Point. If you look closely at the lower left and center portion of the image you can see (in order) green can 1, red nun buoy 2, and flashing green (HORN) 3 just to the left of the exiting ferry boat.
There are five marinas in the immediate harbor area and three of them offer space for transient guests. The largest, by far, is the Nantucket Boat Basin, which has transient slips, Internet access, gas and diesel fuel, showers/restrooms and a complete laundry facility. All of the moorings in the harbor are maintained by Nantucket Moorings, Inc,, and prices are best described as premium. There is anchorage space in a designated area (see chart), but most of this area has already been covered with moorings. If you are in need of repair, Gray Lady Maria is located in the far-south portion of the Harbor an has a series of nun and can buoy that lead customers in past the shoals.
Use NOAA Charts 13241 and 13242.
Red and white Morse (A) buoy NB marks the location of the initial approach channel into Nantucket Harbor and is located at an approximate waypoint of N41 19.018 W70 06.231. Brant Point Light (26 feet above water occulting red four seconds) makes an excellent range when arriving at night.
Once you have picked up red and white Morse (A) buoy NB, set an approximate course of 181 degrees magnetic for .4 mile until you come upon green can 1 and flashing red buoy 2 (both visible in the image above). Flashing green Nantucket East Breakwater Light 3 comes next, and can also be seen in the image above just left of the departing ferry. Also note that most all of both the east and west jetties are submerged. Although the water is shallow on either side of them, more than one boat has made the mistake of foregoing the proper entrance marks and found themselves up on the rocks.
Having safely negotiated your way in past the breakwaters, set a course of around 177 degrees magnetic for .4 mile to intercept red nun buoy 4 and green can buoy 5. Past red nun buoy 4 and green can buoy 5, set your sights for green can 7 and red nun buoy 6, and farther on to red nun buoy 8 and green can buoy 9.
At this point you should be able to see Brant Point Lighthouse to starboard. Continue in toward the harbor, making sure to pick up red nun buoy 10, green can buoy 11, and then green can buoy 13 just off Brant Point. Welcome to Nantucket! The last remaining aid to navigation in the harbor is green can buoy 15, sans a small privately maintained entrance channel on the south end of the harbor.