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|
Wed 12:08am -1.65 knots Max Ebb
Wed 01:28am Moonrise
Wed 03:54am 0.00 knots Slack, Flood Begins
Wed 05:34am 0.67 knots Max Flood
Wed 05:53am Sunrise
Wed 06:29am 0.63 knots Min Flood
Wed 07:57am 0.75 knots Max Flood
Wed 09:36am -0.00 knots Slack, Ebb Begins
Wed 12:20pm -1.42 knots Max Ebb
Wed 04:05pm 0.00 knots Slack, Flood Begins
Wed 04:22pm Moonset
Wed 05:54pm 0.85 knots Max Flood
Wed 07:06pm 0.79 knots Min Flood
Wed 07:37pm Sunset
Wed 08:14pm 0.85 knots Max Flood
Wed 10:00pm -0.00 knots Slack, Ebb Begins
Thu 01:48am -1.66 knots Max Ebb
Thu 02:20am Moonrise
Thu 04:51am 0.00 knots Slack, Flood Begins
Thu 05:55am Sunrise
Thu 06:37am 0.64 knots Max Flood
Thu 07:02am 0.63 knots Min Flood
Thu 08:52am 0.81 knots Max Flood
Thu 10:32am -0.00 knots Slack, Ebb Begins
Thu 01:56pm -1.41 knots Max Ebb
Thu 04:59pm 0.00 knots Slack, Flood Begins
Thu 05:05pm Moonset
Thu 06:49pm 0.83 knots Max Flood
Thu 07:36pm Sunset
Thu 07:49pm 0.79 knots Min Flood
Thu 09:06pm 0.87 knots Max Flood
Thu 10:52pm -0.00 knots Slack, Ebb 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.