Where to See Seal in New Hampshire

Harbor seals are by far the most abundant, with over 75 percent of recorded observations in the state. Grey seals appear in smaller numbers, typically during winter months when they migrate south from Canadian waters. Harp seals are rare visitors, showing up occasionally in mid-winter when ice forms further north. All three species are pinnipeds adapted to cold saltwater, though harbor seals will occasionally venture into tidal rivers and estuaries. The harbor seal's stubby front flippers and rounded head distinguish it from the larger grey seal, which has a longer snout and larger ears.

Peak season runs from January through May, with February and January offering the highest concentration of sightings. During these months, seals haul out on rocks and sandbars for extended periods to conserve energy and breed. May brings another surge of activity as seals prepare for summer. Summer months see fewer sightings as seals disperse to rocky islands and offshore locations. Late autumn through early winter marks the transition when grey and harp seals begin moving into New Hampshire waters from the north.

Rocky outcrops along the Seacoast and tidal islands in the Piscataqua River offer the most accessible haul-outs. Ledges and boulder fields near Portsmouth, New Castle, and the Isle of Shoals support regular seal populations. Seals prefer areas with minimal human disturbance and natural access to deep water for escape. Some commercial boat tours depart from Portsmouth and nearby harbors, providing safe viewing distances. Private beach access is limited during peak pupping season to protect mothers and young, so guided tours are the best option for close observation.

Spotting seals from shore is possible but requires patience and good timing. Rocky beaches and jetties along the seacoast offer better odds than sandy beaches. Look for them hauled out on rocks at low tide, when they rest between dives. Binoculars are essential for seeing seals without disturbing them, as they spook easily if approached closer than 150 feet. Early morning and late afternoon often yield better sightings when seals are most active. Tide tables matter, so plan around low tide when more rocks are exposed.

Harbor seals are smaller, typically 4 to 6 feet long, with a rounded head and small ears that are barely visible. Their coloring ranges from tan to dark grey with darker spots. Grey seals are larger, reaching 6 to 8 feet or more, with a distinctly longer snout and more prominent ears. Grey seal males often have a darker, almost black coat, while females tend to be lighter with white spots. In the water, harbor seals swim with a vertical undulation while grey seals arc their backs. Harp seals, the rarest visitor, are smaller than grey seals with a distinctive white coat and dark spots forming a harp-like pattern on adults.

Yes, populations fluctuate significantly with the seasons. Winter brings the highest concentrations when harbour seals gather to breed and grey seals migrate south from Arctic waters. Spring population peaks around May as seals are most active and visible. Summer sees a decline as many seals depart for more remote islands and offshore rocks where human presence is limited. Fall brings gradually increasing numbers through October and November as migrants return. The seasonal pattern reflects breeding cycles, migration routes, and food availability tied to fish spawning runs.

Several commercial tour operators offer seal-viewing excursions from Portsmouth and nearby coastal towns, particularly during peak season from January through May. These tours use boats to approach seals safely while maintaining the required distance to avoid disturbance. Tours typically last 2 to 3 hours and include narration on seal behavior and biology. Local naturalists and marine biologists lead many tours, providing context on habitat use and the ecological role of seals. Booking in advance is recommended, especially on weekends during February and January when demand peaks.

All three seal species in New Hampshire feed primarily on fish, with diet varying by species and season. Harbor seals consume bottom-dwelling fish like flounder, haddock, and sculpin, along with squid. Grey seals take larger prey including cod, herring, and pollock, and will occasionally eat harbor seal pups. Harp seals feed on Arctic fish species during their northern range and adjust to local populations when migrating south. Seals hunt by diving to depths of 50 to 300 feet depending on the species and prey location. Food availability in estuaries and offshore waters influences where seals congregate and when they remain in an area.