New Hampshire /

Portsmouth Harbor

Bay in New Hampshire · 2,188 acres · near New Castle

Portsmouth Harbor Light across the water at sunrise
Portsmouth Harbor Light across the water at sunrise Photo: N.V. Deremer · CC BY-SA 3.0 · via Wikimedia Commons
  • Portsmouth Harbor from the old fort wall
  • Aerial view of Portsmouth Harbor, August 2023

Portsmouth Harbor is a 2,188-acre bay near New Castle in New Hampshire, with 1 carry-in launch listed here. The launch is free to use.

Channel depths in feet from the Army Corps' surveys of February 26, 2025. Not for navigation.

Channel surveys

  • Portsmouth Harbor and Piscataqua River
    Condition survey of February 26, 2025 by the New England District. Least depth in the channel (35-Foot New Castle Reach): 31.5 ft below mean lower low water (MLLW); project depth 35 ft. Survey sheet (PDF)

US Army Corps of Engineers hydrographic surveys, from eHydro. A survey shows the bottom on the day it was made; channels shoal after high water and change with dredging. Not for navigation.

Kayak and canoe launches on Portsmouth Harbor

Community

Where people who fish, boat and paddle Portsmouth Harbor talk about it. Lake associations, clubs and local groups will be added as we find them.