Tidal currents

[PotomacDaysailer]

Having always sailed on lakes before, I didn't give much thought to the tide the first few times out on the Potomac. But after being becalmed and watching the launch ramp recede faster than I could paddle, I learned that there is a pretty strong tidal current out here. I started paying attention to high and low tide times (conveniently posted at the park gate) so I have a rough idea of which way the current will set, how strong, and when; but how do I get more accurate information, such as charts giving the local flow direction and velocity at various times in relation to high and low water?

 

[Winkfish]

but how do I get more accurate information, such as charts giving the local flow direction and velocity at various times in relation to high and low water?

Try this site. (Google is a wonderful tool.)

http://www.saltwatertides.com/dynamic.dir/potomacsites.html

 

[Ross]

http://tidesandcurrents.noaa.gov/currents08/tab2ac5.html#55
Tide table for the Potomac

 

[rpwillia]

Saltwatertides is the best

When we first started sailing, on of our first outings taught us about tides on the Potomac River. We had a Catalina 22 with an outboard and one day I had taken it home to work in it. Met the wife at the marina and each of us forgot to grab the engine. Since we had just learned to sail on rainbows at the Naval Academy we though no problem. Went out heading south into the wind and watched as we tacked as we were pushed north by the tide and the light winds that could barely fill the sails. Finally near dark got enough wind to make it back to our mooring just as the wind died again.

 

[Ross]

Re: Saltwatertides is the best

Many years ago I saw and purchased a chart book of the currents for many locations in the upper bay. It gives the hour by hour speed and direction of the current based on Baltimore approach for the entire bay north of the bay bridge. I have not seen one since except for very small bits in "Reed's". Even with this I have found that the current from one side of the bay to the other as far north as Turkey Point is extremely variable with edies and counter currents.

 

[Eric M]

One more thing to consider along with all the information you have already been given is the weather influence on the tides. The published information can only be based on the phase of the moon. With the recent strong swell pushing towards the coast from the storms we have had rolling offshore up the coast this summer we have seen incoming tides push nearly 2 knots harder, and tides 2' higher than the usual for this time of the year. The bottom line, the most useful information you will find is what you observe looking at the water and how it is moving relative to fixed objects around you like bouys and pilings.

 

[Ross]

Be aware that the wind against a tidal current will make for some very confused seas. At the mouth of all of the rivers on the bay when the tidal stream from the river merges with the tidal stream in the bay and the wind is against both flows. You will have waves coming from several directions and it will be difficult to steer.