We have decided to use a Yuloh paddle on the Subak. There are a number of reasons for this, including simplicity, facing forward, efficiency, wanting to experiment and probably a certain aspect of wanting to just be bloody minded and difficult. We had seen videos of people moving (even huge) sampans (apparently up to three knots!) and adaptions (e.g. the Ve-scull) that are quite quick. So on Saturday we wasted too much time making a Yuloh while the wind blew, then launched the Subak into a windless harbour a few hours later.
The first experiments with the Yuloh tied onto the transom were surprisingly successful, although quite wrong in many ways. We then built a socket and a pin for the Yuloh and mounted it on the stern. This socket, cut from some hard plywood, was put onto a rounded head screw as the ball joint and was a semi-successful improvement. The plywood had been significantly worked over by the attachment and the work: this seems to be inappropriate.
We then took the design advice from a Yuloh design text (which we had approximately used previously) and made two major changes: the socket was cut from some larch planks we had been left with from someone’s new verandah, given a 45 degree basic drilling to support the correct angle of the yuloh, and the mounting on the stern was raised 30cm. The mounting on the stern is now a simple 12mm steel rod with a round head, shaped with a griding wheel, as recommended here. The main problem is the danger of bending over and sticking the rod in one’s eye!
Tests this afternoon with the new socket are positive, but there seems to be a one sided tendency of the movement. This might be that the hole is asymmetric (it was end-shaped by hand) so that the angle of the yuloh on each stroke is different. It might be that I was not standing approapriately centrally, so that the whole movement was off center. The Subak is assymetric, with the windsurfer dragging off to starboard, so that might have been causing the spin. Tomorrow morning the next experiments and tests will be done. Let’s see what happens.