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|
Thu 12:23am EST -0.00 knots Slack, Ebb Begins
Thu 03:03am EST -1.65 knots Max Ebb
Thu 05:56am EST Moonset
Thu 06:12am EST Sunrise
Thu 06:48am EST 0.00 knots Slack, Flood Begins
Thu 08:40am EST 1.04 knots Max Flood
Thu 12:35pm EST -0.00 knots Slack, Ebb Begins
Thu 01:06pm EST Full Moon
Thu 03:20pm EST -1.86 knots Max Ebb
Thu 05:36pm EST Sunset
Thu 05:47pm EST Moonrise
Thu 07:14pm EST 0.00 knots Slack, Flood Begins
Thu 09:05pm EST 1.06 knots Max Flood
Fri 01:01am EST -0.00 knots Slack, Ebb Begins
Fri 03:37am EST -1.73 knots Max Ebb
Fri 06:11am EST Sunrise
Fri 06:24am EST Moonset
Fri 07:29am EST 0.00 knots Slack, Flood Begins
Fri 09:21am EST 1.12 knots Max Flood
Fri 01:12pm EST -0.00 knots Slack, Ebb Begins
Fri 03:55pm EST -1.89 knots Max Ebb
Fri 05:37pm EST Sunset
Fri 06:44pm EST Moonrise
Fri 07:51pm EST 0.00 knots Slack, Flood Begins
Fri 09:44pm EST 1.17 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.