Isles of Shoals

Every dive at the Isles of Shoals is a boat dive, because there is no way to reach the sites from shore. Captain Rob's Dive Charters runs half-day trips from Rye Harbor, New Hampshire, out to the islands about 8 km (5 miles) offshore; the boat is for certified divers only and works with local dive shops for fills and rentals. Portsmouth Scuba runs guided seal-dive trips from the Portsmouth seacoast aboard the Shining Star, a boat it charters privately for its divers.

The islands are rocky reef and boulder ground. Around Duck Island the bottom rarely drops below 5 m (15 ft), is covered in kelp and carries plenty of fish; the boulders hold lobster, crab, starfish and rock gunnels, and big lobsters are found there too. On the far side of the island, facing the open Atlantic, Mingo Rock drops off quickly to 18 m (60 ft) and more, and the deepest diving reaches about 20 m (65 ft). The Cut, the channel between Duck Island and Shag Rock, is known for its marine life and its seals.

The Shoals suit intermediate to advanced divers with boat-dive certification who want to dive with seals in cold Atlantic water. The area is known for current at times, strong tidal flow can build in The Cut, and Mingo Rock, with its fast drop and heavy surge, is for advanced divers only. Divers who would rather spend their time on wrecks than on seals and kelp can look to Long Island Wreck Valley, the nearest published area, about 240 km to the southwest.