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Where to Go Scuba Diving in Portsmouth

Take a taste of New England's historic maritime culture.
By Jennifer Idol | Updated On April 25, 2022
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Where to Go Scuba Diving in Portsmouth


The author diving in New Hampshire.

Jennifer Idol

The historic town of Portsmouth, on New Hampshire’s short coastline, has its fair share of dive sites and plenty to see for experienced divers and beginners alike. Underwater, divers can find historic artifacts and Northeastern marine life such as nudibranchs, lumpfish and lobsters. Portsmouth, a popular tourist destination with lots of restaurants and activities topside, is busiest June through September, when the weather is warmest, but diving is a year-round activity.


A view from the coast of New Hampshire.

Jennifer Idol

Easy entry and shallow dive sites make diving an affordable activity in Portsmouth, with a few sites available to beginner and student divers. Advanced divers with drysuit certifications will be better prepared for current and cold water, especially at biodiverse sites such as Peirce Island.

Portsmouth features half a dozen sites with easy entry. The Piscataqua River runs along the border between Maine and New Hampshire and opens into the Atlantic. Because of the outflow, dives are best conducted during slack tide (this is a requirement for some sites). Portsmouth sits at the mouth of the river, near a multitude of parks.

Known for nudibranchs congregating on hydroid walls during winter, Peirce Island is rich with nutrients that feed the local marine life. Like other nearby sites, starfish, crabs and lobsters can also be found at Peirce Island. An anemone wall separates this site from others and makes this the deepest of the sites.

The best site for rockweed is Fort Stark, a good beginner dive. During low tide, the rockweed is exposed and matted against boulders, but at high tide, it floats and makes a beautiful photography subject.

Lobsters are most exposed and easy to see at Harts Cove in nearby New Castle, but the real attraction here is finding sunken turn-of-the-century artifacts such as clay pipes and bottles.

Dive Sites

1. Peirce Island

This popular site boasts the easiest of the shore entries, with a quick descent to between 30 and 80 feet deep. Dive only during slack tide, and be aware of boat traffic during the summer. Most divers come to Peirce Island during winter to see nudibranchs.

2. Fort Stark

More than a destination for Revolutionary War history buffs, this rocky shore dive features rockweed, lobsters and hermit crabs, with the occasional lumpfish during spring. Enter through the boulder beach on the northeast side of the peninsula at high tide and head out 200 yards for a shallow dive.

3. Harts Cove

Largely a site for finding historic artifacts such as spoons, cups and ceramics, this cove is a mix of hardpan and muck, with some boulders and kelp. Lobsters frequent the site and are often found near traps. The bottom composition here lends itself to better visibility compared with other sites. Parking and entry are easy and accessible, but make sure to plan your dives around slack tide.


Lobsters are easy to find at easily accessible Harts Cove, where divers can also search the muck for historical artifacts.

Jennifer Idol

Need To Know


Viz varies from 15 to 30 feet; water temps average in the low 40s during winter and low 60s in summer.

What To Wear

Drysuit preferred.

Dive Shop Recommended by PADI

Divers Den Dive Shop, Hampton Falls, New Hampshire

Trip Tips

Seacoast Science Center

This family-friendly museum supports marine mammal rescue and provides educational resources for local wildlife. The cove on the south side of nearby Odiorne Point State Park is a dive site where tree stumps are visible from the surface at low tide.

Albacore Park

Visitors to the park can tour the periscope, control room, engineering spaces and bunk rooms of the decommissioned research submarine USS Albacore. This was the first submarine designed with the cylindrical hull that became the standard for today’s Navy submarines.

Market Square

Every kind of food establishment, from breweries and coffee shops to diners and restaurants, can be found around Portsmouth’s historic square. Numerous hotels also surround the area, and it’s just six minutes from the nearest dive center, making it a great place to stay while visiting.