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|
Tue 02:05am EST -0.00 knots Slack, Ebb Begins
Tue 04:58am EST -1.97 knots Max Ebb
Tue 06:47am EST Sunrise
Tue 08:35am EST 0.00 knots Slack, Flood Begins
Tue 09:29am EST Moonrise
Tue 10:52am EST 1.64 knots Max Flood
Tue 02:11pm EST -0.00 knots Slack, Ebb Begins
Tue 04:11pm EST Sunset
Tue 05:25pm EST -2.34 knots Max Ebb
Tue 07:34pm EST Moonset
Tue 09:19pm EST 0.00 knots Slack, Flood Begins
Tue 11:24pm EST 1.49 knots Max Flood
Wed 02:54am EST -0.00 knots Slack, Ebb Begins
Wed 05:48am EST -1.96 knots Max Ebb
Wed 06:48am EST Sunrise
Wed 09:26am EST 0.00 knots Slack, Flood Begins
Wed 10:16am EST Moonrise
Wed 11:42am EST 1.59 knots Max Flood
Wed 02:58pm EST -0.00 knots Slack, Ebb Begins
Wed 04:11pm EST Sunset
Wed 06:15pm EST -2.31 knots Max Ebb
Wed 08:41pm EST Moonset
Wed 10:08pm EST 0.00 knots Slack, Flood Begins
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.