WOW!! The force of the Merrimack River

DrB · #1 (**permalink**) 10-01-2007

Saturday, I sailed/motored up to the Newburyport from Marblehead to haul the boat (Pearson 10M) for the winter. Great sail until we rounded Thatchers Island/Cape Anne, then we were nose into the wind in 4 to 6 foot seas for 14 nm to the Merrimack River entrance, then Newburyport. Thank god for Autopilot and the Diesel. 3 1/2 h later, were were leaving the big wide open ocean and lining up to for the run between the jetty's into the Merrimack River.

At the mouth were 5 to 6 foot standing waves for 200 yards with maximum height just before the jetty entrance. The waves were so high that 27 foot Searays PB's were getting air born with the enitre hull out of the water. We were going in about 2 h before slack water at low tide, so close to the max ebb flow. Once inside the jetty the water was relativley flat, but near the northern jetty the current was very strong, just were we needed to go.

I had the 27 hp Yanmar at nearly full throttle (3400 rpm) and barely making 1.5 knots. The low point was 1.2 knots. Normally at 3400, I am near hull speed of the boat (7 knots). There wasn't much room to manuever, so if we got below 1 knot, I was going to get concerned. We estimated that the current was 4 to 5 knots in this section.

After twenty minutes of going 1.5 knots, the river suddenly widens and we were up to 3 then 4 knots. It took us nearly 1 h 15 m to get through the jetty and pull up to the harbormaster/city docks; about 2 nm.

We took a photo of one of the channel markers in the current. It was leaning about 20 deg off verticle and half buried under water from being pulled so hard.

Now that we did it (first time), what a relief, but what a rush.

To top it off, the sailboat that pulled in about 30 minutes behind us, was 26/27 foot with a 9.9 outboard towing a dinghy. It went in about 10 minutes before us under full sail and full motor. We passed it once we were going 4 to 5 knots further up river. He said when he went in, ther were times that he was going backwards and had to end up sailing from eddy to eddy for most of the way up.

DrB

sailingdog · #2 (**permalink**) 10-01-2007

Gotta love New England. Earlier this year they were forced to truck migrating fish upstream, since the current was too strong for them to swim back to their normal spawning grounds.

labatt · #3 (**permalink**) 10-01-2007

Had the same problem on the Hudson by the George Washington Bridge. We went up it during almost max ebb (we were running late). Wife took the wheel while I went down below for an hour or so. Came back up and we had only moved a few thousand feet. The even tougher part were the following seas (yes, following) that kept as wallowing around while making almost no headway. It sure was a strange feeling! Our big concern was what to do if we lost the motor, so we unpinned the anchor to get it ready to drop just in case.

gc1111 · #4 (**permalink**) 10-01-2007

You should live behind a barrier island. You quickly learn about the effects of the ebb tide running against ocean waves in inlets. A rivers current just enhances the effect. I live on the south shore of Long Island, and when leaving (or returning to) the Great South Bay a primary consideration is the current in the inlet. I always make it a point to transit an inlet on the flood tide - either when I am entering or leaving. The one time I violated this rule, I got VERY SCARED before getting inside.

sailingdog · #5 (**permalink**) 10-01-2007

You don't want to enter a river at flood tide... then you have the current fighting the tide... and all sorts of interesting waves forming because of that. IMHO, you want to leave or enter at slack water or slightly ebbing...

NOLAsailing · #6 (**permalink**) 10-01-2007

Pretty wild, what we're you thinking looking at the mouth?!

Great boat, by the way. I grew up sailing on my dad's 10M.

DrB · #7 (**permalink**) 10-01-2007

Pictures of Me going through Standing Waves at Merrimack entrance (jetty entrance Ocean side) and the current (at the Channel Marker) just after the jetty (river side).

As usual pictures don't do it justice.

Current at Nav Aid

DrB

sailingdog · #8 (**permalink**) 10-01-2007

Unfortunately, photos and video rarely capture how the waves look or feel.

You really do have to be out there to really understand it.