New Hampshire

New Hampshire has just 29 kilometres of ocean shoreline — the shortest ocean coastline of any coastal state in the contiguous US — but what it lacks in length it makes up in tidal energy. The coast is semidiurnal with a mean spring range of around 2.7 metres MLLW, the signature rhythm of the Gulf of Maine tidal system that intensifies as the basin narrows northward toward the Bay of Fundy. The front beach at Hampton is wide sand backed by a dense resort strip. Behind the beach, the Hampton River and Hampton Harbor inlet carry the tidal exchange, and the charter fishing fleet working the offshore canyons and nearshore reefs launches through the inlet on the ebb. North of Hampton, the shoreline turns rocky at Rye — ledge, cobble, and glacially sculpted headlands running to Odiorne Point, where the tide pools are among the most accessible marine education sites on the New England coast. The coast's inland tidal reach is arguably more significant than the oceanfront. Great Bay Estuary, tucked behind the coastal towns, is one of the largest tidal estuaries in New England at roughly 4,000 hectares — a complex of saltmarsh, mudflat, and open water that drains and fills with each tidal cycle through the Piscataqua River and the shorter tributary rivers that meet it. The estuary supports tens of thousands of migrating shorebirds and waterfowl, significant eelgrass beds, and the soft-shell clam and oyster fisheries that define the region's food identity. The Piscataqua River itself — forming the New Hampshire-Maine border from the estuary to Portsmouth Harbor — is one of the fastest tidal rivers in the eastern US. The tidal current at the railroad bridge regularly exceeds 3 knots, and the river's complex geometry produces strong eddies and shear lines in the approaches to Portsmouth Harbor that demand local knowledge from mariners.