Tidal Currents Can Be Strong in Bays and Inlets and Rivers

[Dockhead]

Originally Posted by Steadman Uhlich

I am starting this thread so CF Members can post anecdotes about the strong currents they have experienced while voyaging or cruising. Please post your own experiences, including your observations or memories, from anywhere.

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I just returned from a 1200nm 21 day voyage from Florida to Maine. I was aboard a 53 foot sailboat. We sailed and motorsailed offshore the entire way (no ICW) and during that time I had a chance to observe tidal currents in several locations, as we pulled into a few ports for fuel or provisions or parts or final destination. We motor-sailed through some tidal currents that were strong and impressive.

A few times I could see our boat speed (through the water) was 7 knots while our SOG was 2-3 knots! (More throttle needed.)

The boat I was on had a reliable 120hp Diesel engine, and swung a big fixed prop. So we had the ability to power through when we wanted.

Of course we timed our entrances and exits to use the wind and currents when possible. Even so, when on a voyage like this I had the opportunity to see significant currents.

What made this aspect of this voyage memorable for me was the variety of locations seen in such a short period, allowing my observations to be fresh in mind.
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Ponce Inlet Florida. (which flowed fast like a river)

Chesapeake Bay Entrance. (which flowed fast like a river)

"The Race" in Long Island Sound. (which flowed fast with rip)

Montauk Point (entrance to Long Island Sound). (which flowed fast like a river)

Cape Cod Canal (which flowed fast like a river, with eddies and some serious back-flows along the shore). I had heard about the Cape Cod Canal flow from a previous captain last year, so was prepared to see it. I was impressed by the Canal.

Penobscot Bay in Maine (which flowed fast like a river between Islands)
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Even when transiting these areas at favorable times and in good weather, the currents can be fast and strong. Large ATON Buoys were leaning on the currents. Crab and lobster pot buoys were submerged.

If one had an underpowered sail or power boat and low or no wind or unfavorable wind, it could be very challenging.

It made me think of the challenges of the old days of sail when large ships had no engines.

I watched the tide turn on two tidal rivers on which we were moored. It was interesting to see the surface of the fast flowing water go one direction for hours, then as the tide changed go the opposite direction for hours.
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Those are my observations. What are yours? Post your anecdotes below.

Nice post, Steady.

I never had any experience with strong tides until I started sailing here. That was jumping into it with both feet, I'll tell you.

The scariest thing about strong tides is tidal races and the sea states they can generator the dreaded tidal race at Portland Bill has been known to swallow ships whole. Sailing coastwise along the English South Coast, you have to deal with a number of them, and often you have to go around them. Or in some cases, INSIDE them, which can be terrifying!

Some tidal races -- like the Alderney Race -- can reach 12 knots at springs.

You can't sail anywhere around here without taking the tides into account and planning where you will be when. A favorable tide sure tightens up your tacking angle (in relation to the ground) -- a sweet bonus when you're trying to get upwind!


Not really relevant to anything, but just one remark -- you talk about "powering through" a strong tidal current. I would say there really isn't any such thing -- your boat doesn't know anything about the ground -- she sails in water. So you can't really "power through" a current -- you get somewhere in relation to land by the sum of the vectors of the current plus your own motion through the water. You just get there slower if the current is against you. You can compensate to some extent by sailing (or motoring) faster, but you could do exactly the same thing in a favorable tide, to.