Relying on info detailed in the attached book, I can’t immediately answer your question, but I can find the book and post the citation.
This is the most valuable book I’ve found for kayaking. Contrary to a few reviews on the book, the information is not too technical to understand or to retain for practical application.
Under the heading on the influence of wind, wave, tides and currents, he explains that a 10 mph wind blowing unobstructed for 12 hours will generate a .6 mph current. I just accept his comments at face value and found them helpful in assessing how forces impact performance. I’ve satisfied my own curiosity through analysing GPS data.
As I explained to you in email messages, I don’t focus much on technical kayaking skills. You’ve developed greater technique in a few years than I’ve been able to hone over 15 or more years of paddling. My primarily interest is paddling efficiency and understanding the forces working for or against me. With the help of that book, I better understanding the paddling environment so I can best harness energy reserves. That helos me to achieve virtually flat line average speeds over the duration of a trip, whether going into or against conditions.
You’ve seen my speed graphs. How effectively I’ve been able to manage that goal is for you to decide, but I’m satisfied. While most kayakers paddle for fun and aren’t the least bit interested in such voodoo, I use each trip as a practical lab to test the author’s theories. I loaned the book to someone and lost track of it, so I recently bought another. I loaned another book to someone and lost track of it. That book details the history and features of the Chesapeake Bay, as well as the dynamic forces that make it nutrient rich for acquatic life. It covers such things as salinity distribution, the churning action of heavier salt water flowing under the outgoing fresh water, estimating distances, the curvature of the earth on line of sight, drift and ranging to stay on course. The trip course I take is often selected based on chasing the tide line which is highly visible during peak pollen, because it creates a distinct green line on the water surface. In a kayak, the subtle forces are instantly felt while paddle through the churning water. I posted pictures to you of the currents that swirl around navigational aids.
While others are watching ducks, my attention is on the force of the water and turning it to my benefit or how to fight it most efficiently. Sorry I can’t verify it all of this, but I do believe land bound water bodies of water are influenced by lunar forces; they just aren’t as pronounced. Realize that especially the moon exerts a constant force that pushes the water in a perpetual circle around the earth. It shows up locally as a rise and fall, but it’s actually in constant motion in one direction, unless it gets trapped. The Chesapeake Bay is a unique channeled body of water in that the length results in a high at one end and a low at the other, and similar conditions throughout. The tide charts are mainly based on lunar influence, but the wind forces, especially when blowing north or south, have a major impact that can double the effect of the normal tide range (between 1.2 or 1.8 ft). The turn at Battery Point on my test course is a tidal datum point. It takes about 30 minutes for the tide to reverse 5 miles further north in the narrow feeder streams. If you understand the intervals, you can ride the tide up those winding channels, then gauge your prediction by how closely you arrive at the reversal. With the right counterclockwise air pressure system off the coast of Virginia, water is forced up the bay, and when combined with a strong wind out of the south, tides can inceease by 3 ft. That allows further exploration into the marshes.
Sorry for imposing this topic on uninterested viewers, but I know you, Steve, have an interest in such topics, and that you want to paddle tidal waters. This explaind why speed calculations and timing is so important to me. It “can be” like a plane jumping into the jet stream, or simply arriving on location at the right moment.
One benefit to accurately predicting peak tide is bei g on station to ride tidal outflow from water bottled up in several basins that have restricted entrances. Fairlee Creek (10.5 mile trip across the bay, a 4.45 hour round trip) and Still Pond, over 18 miles up the bay, an 8 hour round trip are two examples. While the trip across the bay isn’t influenced much by conditions in the right boat, the trip up the bay can be helped by a 2.4 mph tidal inflow, or hindered by a 3 mph outflow, or traversed during a mostly nuetral phase (my one 38.75 mile round trip to Still Pond faced an outflow and took 8 hrs 20 min.
These attachments are extracted from google searches to give a little insight.
I think you would enjoy paddling this area. While some consider the Bay treacherous and unpredictable, I believe it’s more predictable and friendly to the paddler than bodies like the Great Lakes or San Francisco Bay with the cold water, or the high tidal influence of the inlets of British Columbia or the coast of Maine.
