Hickling Broad (Norfolk UK) fitted to Seahawk 17 "C-Auk)

The Seahawk is a design of small cruising yacht built in the East of England between 1969 and 2004. About 500 were built. I was looking for the smallest practical keelboat that I might mount my wings on. For those that are interested the boat has it's own website here. The one I acquired is called "C-Auk" and is one of the last ones ever built. She is based at Whispering Reeds Boatyard. Hickling, Norfolk UK.

Initially the boat was set up with the smaller wing above, of only 20sq ft. Performance
was as expected to be slower than when the wing was on a light beachcat.
But it worked! Better in a fresh breeze, would do up to 2 knots on a broad reach.

I was curious as to how well the wing would fair left permanently up. Just weathervaning in whatever breeze came along. I was pleasantly surprised that when I took it down after 16 days - I could see no sign of wear or deterioration.

Next step was to set up with the extra mid section which brought the sail area up to 25 sq ft. - still very small. as below.

With this there was a noticeable improvement in performance. Reaching (on a reach) 2.5 knots in a fresh breeze.
At this time I introduced a tiller pilot. Which meant I could leave the helm, and this achieved completely automatic sailing, no sail adjustment required and no course adjustment required!

This was one of my aims. This meant that after you had set your course, there would be nothing to do until you reached your destination however the wind shifted.

In this configuration the rig was left up mostly unattended for 14 days.
The weather had been fine, but suddenly broke with a day of violent winds and torrential rain.
Here is a video here of how the wing weathered the storm when moored.


Youtube may like to take you to further videos. Ignore this and come back here. Otherwise you will miss the rest of the story!)

As you see the rig was weathering the wind and rain well.
Again there was no sign of obvious damage, only minor water ingress which can be easily plugged in the next design.

The beauty of the system is that  when you want to sail, you just get on the boat, unhitch the mooring lines, put the "throttle" in drive and just go. No sail to fit, no ropes to pull and adjust. - you don't have to worry about the wind direction, the rig just weathercocks to the right position to drive. Makes for a very pleasurable experience. I know some may not agree. But for those that like an easier life, and still want to enjoy the quietness and peace of sailing without all the hassle - it's just the thing.

Here's a copy of the placard I put on the boat, so that curious passers by would have some idea what it was.

Automatic Sailing system.

 Three new ideas in one.
 1. A wingsail, wingsails are more efficient than sails because they have less drag.

 2. Self Trimming. Wingsails need to keep the angle of attack more accurately than a conventional sail. Therefore a tailvane, behind the main wing is used instead of manual sheeting.

 3. Automatic control. A mechanical system operated by a cam, keeps the wing at the optimum angle at all times.

Whatever heading the boat is on, the wing is adjusted to the most effective angle. It's self setting and self tacking and self gybing. Control is by one lever - Forward, Neutral, Reverse. There is no other control required. No mainsheet or any other ropes.
 Whilst moored. The control lever is set to neutral position. The wing is left up. The teardrop section of the wing has even less drag than a round mast and weathercocks into the wind.
 More complex to build than a conventional mast and sails. But the payoff is the complete simplicity in use.
Peter Worsley 01603 469066. More information: www.sailwings.net. www.windthrusters.com

1st Wingsail model 2nd Wingsail model Fullsize Boat Electric Power What are Wingsails? Contact
Construction Method Windthrusters Rotary Sailing

Any Questions? click here