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|
Sat 12:59am Moonset
Sat 02:20am 0.00 knots Slack, Flood Begins
Sat 04:19am 1.27 knots Max Flood
Sat 07:17am Sunrise
Sat 08:11am -0.00 knots Slack, Ebb Begins
Sat 10:52am -1.78 knots Max Ebb
Sat 02:34pm Moonrise
Sat 02:47pm 0.00 knots Slack, Flood Begins
Sat 04:44pm 1.20 knots Max Flood
Sat 05:34pm Sunset
Sat 08:26pm -0.00 knots Slack, Ebb Begins
Sat 11:20pm -1.99 knots Max Ebb
Sun 01:09am EST Moonset
Sun 02:18am EST 0.00 knots Slack, Flood Begins
Sun 04:18am EST 1.31 knots Max Flood
Sun 06:18am EST Sunrise
Sun 08:14am EST -0.00 knots Slack, Ebb Begins
Sun 10:55am EST -1.86 knots Max Ebb
Sun 02:10pm EST Moonrise
Sun 02:49pm EST 0.00 knots Slack, Flood Begins
Sun 04:33pm EST Sunset
Sun 04:44pm EST 1.20 knots Max Flood
Sun 08:32pm EST -0.00 knots Slack, Ebb Begins
Sun 11:21pm EST -2.03 knots Max Ebb
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.