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 12:00am 1.67 knots Max Flood
Sun 03:25am -0.00 knots Slack, Ebb Begins
Sun 05:09am Sunrise
Sun 06:33am -2.43 knots Max Ebb
Sun 09:16am Moonset
Sun 10:24am 0.00 knots Slack, Flood Begins
Sun 12:31pm 1.61 knots Max Flood
Sun 04:09pm -0.00 knots Slack, Ebb Begins
Sun 06:57pm -2.09 knots Max Ebb
Sun 08:25pm Sunset
Sun 10:38pm 0.00 knots Slack, Flood Begins
Sun 10:46pm Moonrise
Mon 12:50am 1.64 knots Max Flood
Mon 04:14am -0.00 knots Slack, Ebb Begins
Mon 05:09am Sunrise
Mon 07:22am -2.40 knots Max Ebb
Mon 10:27am Moonset
Mon 11:13am 0.00 knots Slack, Flood Begins
Mon 01:22pm 1.63 knots Max Flood
Mon 05:02pm -0.00 knots Slack, Ebb Begins
Mon 07:49pm -2.08 knots Max Ebb
Mon 08:24pm Sunset
Mon 11:21pm Moonrise
Mon 11:34pm 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.