Yes it works. Our first trial session just to use a power kite in lieu of classic sails to propulse a boat simply worked!

Actually when a kite can pull a kite surfer.... more can nearly shoot him out of the water on many meters in the air, then why shouldn't it be able to pull a boat.

Our first test was a full success. We could sail and record interresting measurement data. See our video in the gallery or on YouTube. The recorded data will be put together and completed with a report soon. All will be available for free on our internet site www.kitecruiser.org. And here the full story...

It is Friday afternoon, we are preparing the boat in Heligenhafen. The always good mooded harbour master in Heiligenhafen is asking us a bit wondering where did we forget our mast and rig. His eyes are getting even more round when hearing to our plans.

In the evening we are reviewing all the measurement equipment taken on board to be sure all is working and to let Sebastian get familiar with the equipment and corresponding software. Sebastian will take the role of „measurement officer“. Indeed some have been flying kites on boats before us, but no one has published any data till now (at least I did not found).

On Saturday morning, after a fantastic breakfast in the Marina of Heiligenhafen – never underestimate a good mood on board ;-), we take a course on Fehmarn. We are about to collect our 3rd team member in Lemkenhaven. Michael is an experienced kite surfer and we need his experience to enure a safe and successful start.

In Lemkenhaven we make the kite ready. We have a 15m² hybride kite „Prime“ from „Trans“. According to my estimations, done with the little of data available on the net, but with shipbuilder and sailor's experience, 15m² shall be the perfect size for our 22ft Sasanka for light to moderate wind.

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Michael is showing us how to prepare a kite in a way to be sure the line do not get tangled. For the start of the kite we need a special procedure. This cannot be overtaken directly from the kite surfing, where the kiter streches out the lines on land and gets a help from a buddy to start the kite on straight lines at the wind window edge. The boat is only 6.6m long and the line abt. 25m so in our case all needs to be prepared on the deck. Then the kite will be let to drift away and we have to do a water start. In case of a problem on the lines preparation, the whole kite test would need to be stopped and back to the harbour for new turn of line clearing.

The kite is also fixed to a specially designed mechanism. We have to ensure a direct transmission of the force generated by the kite to the boat. Otherwise the kite pilot would fly away from the deck. The mechanisme is designed in a way to be able to install a small elecronic crane balance – our best low cost device to measure the force.

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Yes, measuring – important in this test. The force is one of the most important parameters. Unfortunately the crane balance has no interface to a computer. The solution is simple: a small webcam over the LCD Display will allow to shoot pictures every second. Unfortunately the data then need to be typed in „per hand“. Ok, but for the wind speed the anemometer communicates with the netbook per USB. To complete the nautical parameters a nice GPS mouse will allow a raw NMEA data dump to a file. All these requires to cable the boat. Luckily white USB cables as well as a blue tape let the boat still to conserve its nice look and not to turn to a package of cables.

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All stuff working, the kite packed, the kite security systems checked, the team is on board, the sun is shining, we can start for the adventure.

On Saturday we are three on board:

Sebastian – the „measurement officer“
Michael – the „kite profi pilot“
Maciek (myself) – the „helmsman“ and action organisator

The sunshine is fantastic. Our small gopro-like camera already smiles of joy. It will have to record continously remaining fixed on the aft reling. We have no extra camera team. Hopefully by the next test we will be able to record nice videos also from an assisting boat.

The wind is quite light. Only 5-8 knots. For a first test actually not so bad. Michael doubts is we can confortably keep the kite in the air. But let us see outside. Michael leads us close to the area where a small wind amplification offures due to the shore arrangement close to the Fehmarn Sund bridge. All the boats we are passing by wonder what are these guys doing on a boat without mast.

It is time. We take out the kite, fix the chicken loop to our supporting construction and start to inflate the kite. On board is seems huge. Luckily the boat can be easily stabilised in a half wind drift, so we have the full length to deploy the kite. Inflated finished, the kite is dropped into the water. Now comes the big question: Are the lines clear? The kite drifts away and... Youpiii! The lines are completely clear! Michael – thank You for the good hints!

So let is kite sail! The waterstart is easy! Few check how the kite behaves in the air – it is its first flight as well and …. Yes, we are already sailing! It really works. The kite is pulling the boat forwards. We are mainly sailing the beam reaching (half wind) courses and up wind, close reach ones. On teh broad reach and running the apparent wind will be to weak.

It is time to tack! Actually in order not to cross over the steering lines we simply jibe. Funny under the kite it makes nearly no difference. The main issue is to bring the kite at 12 o'clock and then we can do with the boat what we want! Funny we can even slow down the sailing by easily bringing the kite on the other side of the wind window.

The sailing is very calm and comfortable. The boat has, as expected, nearly no heel. No wonder, the heeling lever is very small. The maneuvrability of the boat is very good. Attaching the forces to the mast step was a perfect solution. The sails center is usually close to this point.

Now we can profit of the nice time and try to tack / jibe several times. We also sail with a parked kite as well as we boost the sailing by an active flying of it. The 15m² seem to be the very well choosen size. Choosen with a bit of luck based on some informations and mainly estimations.

After two hours the wind is getting even weaker. It is time to come back to the harbour. The first day is a full success! We land the kite on the water, collect it on board and back to Lemkenhafen. Last check of the measurement equipment – yes we have good data – quite much....

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The champain can be openned! Yes for today the job is done, we can now discuss the next improvements and prepare for tomorrow.

On Sunday the wind is slightly stronger and the sun is unfortunately not present any more. We cannot come back too late to Hamburg. We shall have only one hour for sailing in the morning.

But let us use it as well. Again beam and close reach are very successful. However what is the most interesting – we reach about 6 knots over ground speed on a running course! This is possible only by an active flying of the kite in „eight“. This allows to check the actual hull drag. Six knots it is actually the hull speed limit for a 22 ft. boat. We reach it with a mean force of abt. 450 N. All this by only 6 knots of apparent wind. Such a sailing is absolutely not possible with a classic rig! A big „whaouh“ for our kite.

As all the good time, it reaches quicly the end. We take my Sasanka 660 back home, where it can have a rest on its trailer before we can organize the secont campaign of tests.

We have collected a large ammount of measurement data. They need to be processed now to be usable. They will be all published on our intenet site www.kitecruiser.org. My intention is to make this alternative propulsion for boats more popular, therefore the idea of the open project arround.

A video from the tests is already available on our site and on YouTube. I hope You will like it.

Here I would like to thank very much to Michael and Sebastian, who took part in the tests. Without their help this test would not take place. But we want to continue! This is simply the beginning!

If You find the innovative idea of sailing with a kite interresting, please do not hesitate to contact us, to join us, to support us by any means. Already telling about it to friends is a help for us!

Kite sailing for the future!

Maciej Radon

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