See also this

First sunny spring day around here so we went out to try out the flip-out disc sail I made over the winter on my Llama and Steve’s Big Kahuna. Wind was forecast at about 8 mph but was gusty – a bloke in a dinghy sailboat said it was up to 15 mph.
Folded and clipped on the packraft, the sail sits out of the way and can be opened and – more importantly – closed easily with a twist, as long as you have a clip of some sort to keep it closed (and that clip is attached to the sail so it does not spring off and sink to the bottom of the lake…).

Initial impressions were disappointing, I did not rip off across the reservoir like a hooked marlin out of a Roadrunner cartoon. But watching the vid back it’s clear the boat did noticably drift downwind across the reservoir with the sail aloft, often at speeds similar to paddling (about 3 mph). Problem with the sail on the Alpacka was the boat soon turned off the wind one way or the other, swinging left and right. The pointier Kahunayak was better, especially once Steve trailed his paddle like a skeg. Didn’t get to try that on the Llama as I was fiddling about with the string trying angle the sail so as to steer the boat into the wind. This worked quite well in correcting the direction as you can see in the vid, but staying in that position was a problem.
Could this be due to ‘wind-spill’ off the flat disc sail which lacks dishing like a WindPaddle? Maybe. It will be interesting to try it on my ruddered Incept IK when it turns up, as well as the new-shape Alpacka which I am picking up next week.
More testing to come this summer up in windier Scotland with my all-new packboating flotilla. Or just enjoy this 2014 video from Finland by JP. More here at leftbound.