The idea is really simple

A wing is a much better propulsion system for boats than a sail.

 A wing has more forward thrust, has less drag, sails higher in the wind and has less heeling force than a single skin sail.

We wanted to find out how to get all these benefits on our boats. We wanted to find out if it could be done on any boat.

We tested it on a catamaran. It worked.

We tested it on a dinghy. It performed extremely well.

So we funded a company. The mission: Wing sails to the people!

Seriously, we think we have something really cool, and we are looking for pilot costumers. Maybe there are other sailors out there whowant to sail faster up wind with less heeling force?



The technology is patent pending

Since the idea is really easy to grasp, we needed to protect our invention.

The patent pending wing sail has double skin and rotating inner structures – called Tvibits – that forms the shape of the wing. (You can even design and order your own unique wing profile if you want.)

Handling is easy

Tacking is done with one pull on a thin rope, reefing and packing is done the same way as with a single skin sail. And the beauty of it all: The Tvibit wing sail fits any mast on any boat. You can take down your old sail and hoist a Tvibit wing sail and just go flying within minutes.

Made for sailors – by sailors

We have worked on this patent pending technology for about six years. Now we are confident that we can offer Tvibit wing sails for boats up to 30 ft. For bigger boats there are still some technical challenges to be solved. We are working on it.


Technical stuff

We are working on getting sound data on exactly how fast the Tvibit wing is. Boat speed over the water, VMG and boat heeling will depend on many factors, not just the Tvibit wing. A heavy boat might benefit a lot from less heeling on a long cruise leg, while a planning trimaran might benefit more from a sharper Angle of Attack (AOA).



Velocity Made Good: So far, we have measured improved Angle of Attack with the Tvibit wing. The wing, mounted on a 22 feet racing dinghy, sailed with less than 15 degrees to apparent wind in very disturbed wind. Below is a track of the boat with the Tvibit wing.

Baot speed is about 4 knots. True Wind Angle is 32,5 degrees. This gives us a VMG to wind of 3.37 knots.



less heeling

Reduced Heeling Force: Theoretically, a wing shall have up to 50% less heeling force than a single skin sail. (See for example  Eltringham 2004:44) On our test boat, we can comfortably sit and talk on the gunwales in conditions that normally would call for a trapeze. The upsides are obvious. You can carry more sail as the wind picks up and sail even faster. You can plane in higher angles if you have a planning boat, and you can sail a lot more comfortable if you are on a cruising voyage.


More thrust: The wind flows over the wing and creates lift and drag. On a boat, these forces are converted into forward thrust and heeling force. Any wind creates a larger thrust force on a wing than on a single skin sail, just as it creates less heeling force. How this is felt on the boat will vary very much from vessel to vessel. In our test sailing we found it necessary to have a jib (since we have a standard rig) to accelerate the boat. 

Weight: The Tvibit wing consists of double cloth and carbon Tvibits to shape the airfoil. It is obviously heavier than a single skin sail. We are constantly looking for ways to reduce weight. Anyway, this is just a handling matter. When sailing, the extra weight force aloft is many times surpassed by the reduction in heeling force.

Price: Until now, the prototypes has been hand made.  We have had the best carbon and composite builder in Norway to help produce Tvibits, and we have had one of The Netherlands best sailmakers to work on the double skin sailcloth. We are now looking into 3D printing and other ways of production to lower the cost without the loss of quality. If you want to find out how much a Tvibit wing sail would cost for your boat, please just contact us. We are considering subsidising important early movers that can help us test the wing further.

Do you, or do you know anybody who wants to be a pilot costumer? We can promise a really cool high-performance wing and unprecedented costumer support. We want you to love the feeling of flying on the water. Since we are in an early phase, your feedback, ideas and critique is of the highest value to us!