Nantucket, MA tide times

Nantucket sits 48 kilometres south of Hyannis across Nantucket Sound, a shallow shoal-filled body of water that has claimed hundreds of vessels over four centuries of commercial maritime traffic. The island itself is a glacial outwash deposit — flat, sandy, and relatively low-lying — with the tidal regime that comes with open Atlantic exposure filtered through the Sound's geometry. Mean spring range at Nantucket Town pier runs close to 1.0 metre, making it a moderate-energy microtidal environment compared to the larger ranges of the Gulf of Maine just to the north.

The two daily tidal cycles arrive in a semidiurnal pattern with some diurnal inequality — the two daily highs are frequently of slightly different heights. The predictable alternation between high and low drives the tidal currents through Nantucket Sound and through the Inlet channels flanking the island. Nantucket Inlet on the west side of the harbour is the main tidal exchange point for the Great Harbor, and the current through the inlet is noticeable on spring tides, running to around 1.5 knots at peak flow.

Nantucket's history is dominated by the whale fishery. In the 18th century, Nantucket whalers were among the first to hunt sperm whales in the Pacific Ocean, and the Nantucket Whaling Museum on Broad Street holds one of the most significant collections of whaling-era artefacts in the world, including a 46-foot sperm whale skeleton. Herman Melville based Ishmael's voyage on Nantucket whaling practice. The grey-shingled architecture of the town and the warren of lanes leading to the harbour front reflect the prosperity of that era.

Brant Point Light, the smallest of the US lighthouse towers (only 10 metres tall) and the second-oldest lighthouse site in the country, marks the east side of the Nantucket Harbour entrance. The tradition of throwing coins from the ferry railing as Brant Point passes is widely observed among returning visitors — a superstition for ensuring a return trip.

The ocean beaches on the south shore — Surfside Beach, Madaket Beach, Cisco Beach — face the open Atlantic and receive the South Atlantic swell with energy that the Sound-facing harbour shores don't see. Cisco and Madaket in particular are popular surf spots in autumn when NE and E ground swells wrap around the island's western end. The tidal state at these beaches affects the break character: lower water tends to expose more of the sand bar system and steepen the waves; higher water tends to produce longer-period waves over the underwater bar.

Great Point at the north tip of the island, accessible only by 4WD on a beach permit, is one of the most productive shore-fishing spots in the northeast US. The rip off Great Point — where the Sound and the open Atlantic interact — concentrates baitfish and predators alike; striped bass and bluefish are taken here from April through November. The lighthouse at Great Point was rebuilt in 1986 after the original was lost to a 1984 storm.

Predictions on this page come from Open-Meteo Marine, a gridded global ocean model. Accuracy is typically within plus or minus 45 minutes on timing and 0.2 to 0.3 metres on height — model-derived, not from a local gauge. For authoritative US tide data, consult NOAA CO-OPS at tidesandcurrents.noaa.gov.