How long does tide stay slack between movements (generally)??
In general how long does the tide stay full slack in the upper Chesapeake, Patapsico area??
Or another way to ask, how long from the listed low or high tide until water starts moving again??
I'm south of you ....but generally 1 hour on each side you will see slow down.
And remember high tide does not equal slack water.
Nor does low tide.
Here in middle bay, with no contrary winds, the current may run 60 to 90 minutes after high or low water time has passed....
Here is what im trying to figure out. Friday im heading down from PA, bout an hour drive. If 7:15 is high and 2:45 is low the peak moving water shouold be roughly 10am -2 pm???
Im trying to time it to have moving water for the most time i can without being on the water for 8 hours.
Last sat. started crabbing at 6:30 am and caught the end of tide and got some, then is slacked off unitl afternoon when the tide ran good again and we ended with a 1/2 bushel. Dont mind spending all day just wanna see if the moving tide is better vs. the early morning/low light conditions. I will stay long enough to get enough to make the trip worthwhile. I love being on the water at sunup as well but 8-9 hours in the heat and then a drive on the beltway home can make for a looong day.
I appreciate any thoughts or feedback.
Mattpa - I would try to get on the water around 730 and setup by 800-830. That way you can crab the falling.....you will know when it turns off, just rap it up then and go home with hopefully a bushel.
True slack water occurs for only a few minutes. However the rate of current is so slow before and after slack tide that it may "appear" to be slack for a long period of time.
Here is a NOAA chart showing the exact time of slack water for Baltimore Harbor.
These NOAA charts are yearly charts. So, you have to scroll down about half way to get to todays date (June 29, 2011). These charts are available for many areas of the Bay. Just click on the "Prediction" link next for the area your interested in at the following WEB site:
In some areas of the Bay, slack water may occur very close to the high and low tide. In other areas of the Bay, the exact point of slack water may occur an hour or more before or after the published high/low tide. It varies greatly depending upon location.
Great! Thanks so much for the feedback!
The term slack tide is a misnomer. Tidal flow is constant. The rate of flow and direction is what changes. If you have ever been at anchor with a group of boats (chumming) when the wind is dead calm you can observe the tide change direction. If the tidal current stops its only for a split second. All of the boats will be positioned facing the same direction against the tide and all will swing 180 degrees at the same time if they are abreast of each other without touching. The first time I saw this it made me realize that if the tide truly went slack the individual boats would be in different positions.
I agree that slack tide is a misnomer; there are tides and there are currents. "Slack" refers to a current slowing down and stopping momentarily prior to shifting direction. In mid bay, I've found that maximum ebb current occurs near "low tide" and maximum flood current occurs near high tide. Slack current occurs more closely to mid-tides, not closely to high or low tides. That's exactly opposite of what I used to believe; that currents stop at high and low tides and slowly begin moving in the other direction after each high or low tide.
For example; today's high tide at Herring Bay on 7/16/11 is predicted to be at 5:28pm and the predicted maximum flood current is at 5:49pm with slack currents predicted at 3:13pm and 8:27pm on either side of that flood current.