Oar+Some- Propulsion

This is a description of the propulsion system for Oar+Some- which is pretty much the central feature of the design.

You might want to look at the video again - to be reminded of how the paddle moves.

If you look at the picture above, you will see that the rider has finished pushing with his left leg, and consequently the right paddle blade is towards the rear, and at the end of its power stroke.

During this power stroke the right blade remained securely under water at just the right depth automatically. This is because the blade is angled a few degrees off the vertical, and therefore the reaction from the water on the blade gives it a tendency to dive, but it is then constrained to not go too deep by a kind of string arrangement. The string (or tie) is not shown, but you can see the lugs for it in this picture.

During the power stroke, the water is pressing on the rear face of the paddle blade and maintaining this submerged position, but of course the rider's pedalling action is cyclic and the blade slows down and ultimately stops at the end of the power stroke. As this begins to happen, and assuming Oar+Some has some forward momentum already, the water now is pressing on the front face of the paddle, which causes it to rise out of the water. As the right blade leaves the water, the paddle's momentum causes the left blade to enter the water, and the rider times his new forward thrust with the other leg to this point - and so begins the power stroke on the other side.