Here are some shots of the actual drain and where it is located. The first shot was while standing directly on top of it looking down (HOLD ON TO THE CAMERA!), and the second is shot looking back and down from the bank. The drain in the second shot is located in that finger of water pointing to the left at center.
The photo on the left is looking toward the drain from above where water is flowing into the pool. The photo on the right is from the drain looking toward that inlet.
Boat #8, not looking too seaworthy right now. This boat was elegantly made, not sure of the age, but guessing around the nineteen-thirties.