River traffic. Piscataqua River currents restrict travel by tankers and other large vessels to slack tide, roughly four hours a day. See chart below for slack tide at the entrance to Portsmouth Harbor. The entrance is nearly three miles from the location of the PortsmouthNH.com's HarborCam. Slack tide at the Harbor Cam is roughly a half hour later. A schedule of shipping in the Piscataqua is not available.
Currents. The swift currents of the Piscataqua River make it among he fastest flowing tidal waterways in the Continental United States (NOAA list of 50 fastest in North America; look for "Nobles Island, north of"). The ice-free deep-water channel has been used for shipping since the 1600s.
Piscataqua River Currents|
Sun 01:50am EST -1.55 knots Max Ebb
Sun 04:53am EST 0.00 knots Slack, Flood Begins
Sun 05:04am EST Moonset
Sun 06:56am EST 0.99 knots Max Flood
Sun 06:58am EST Sunrise
Sun 07:42am EST 0.97 knots Min Flood
Sun 08:55am EST 1.03 knots Max Flood
Sun 10:50am EST -0.00 knots Slack, Ebb Begins
Sun 02:33pm EST -1.88 knots Max Ebb
Sun 03:09pm EST Moonrise
Sun 04:54pm EST Sunset
Sun 05:38pm EST 0.00 knots Slack, Flood Begins
Sun 09:32pm EST 0.97 knots Max Flood
Sun 11:20pm EST -0.00 knots Slack, Ebb Begins
Mon 02:32am EST -1.56 knots Max Ebb
Mon 05:42am EST 0.00 knots Slack, Flood Begins
Mon 05:45am EST Moonset
Mon 06:57am EST Sunrise
Mon 07:42am EST 1.01 knots Max Flood
Mon 08:43am EST 0.98 knots Min Flood
Mon 09:39am EST 1.01 knots Max Flood
Mon 11:36am EST -0.00 knots Slack, Ebb Begins
Mon 03:04pm EST -1.90 knots Max Ebb
Mon 04:05pm EST Moonrise
Mon 04:56pm EST Sunset
Mon 06:23pm EST 0.00 knots Slack, Flood Begins
Mon 10:17pm EST 0.97 knots Max Flood
About the Piscataqua River. This Piscataqua River is a 13-mile long tidal estuary formed by merging of the Salmon and Cocheco rivers. The river, which separates Maine and New Hampshire, also drains Great Bay, a National Estuarine Research Reserve site. The last 8.8 miles of the Piscataqua River constitute Portsmouth Harbor, which stretches across New Castle, Portsmouth, and Newington, and the Maine communities of Kittery and Eliot.
New Hampshire-Maine border. The N.H.-Maine border lies in the middle of the Piscataqua River. Its exact location was the subject of a long-running dispute settled by the U.S. Supreme Court.
What kind of name is Piscataqua (piss-cat-a-qwa)? Easy for you to say, but not so easy to spell. See an extended examination of the origin of the word at SeacoastNH.com and 20 ways to spell Piscataqua.
More information. For more about the Piscataqua River, see the Army Corps of Engineers Water Resources web page.