I got some interesting insights from a rowing scientific test detailed in Jimmy Joy’s book about “Flow in rowing”.
He has a controversial coaching suggestion; a double hand feather for sweep rowing is more efficient.
Jim had this tested in the MIT hydraulic lab in 1964 by one of his oarsmen athletes, Dr Dennis Ducik.
“In sweep rowing if you relay on the inside hand only to release then the thumb acts as a block to the flow of the handle and the wrist breaks severely. The two-handed release fosters flat wrist rowing.”
Want to test this out and let us know if it works for your crew?