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Building a real boat


It has been a while since the latest posting. However, the development of the boat is ongoing. Many small and large things have changed. For instance, the A-mast has been changed into a single mast. The board have been redesigned a number of times, based on testing with the scale model.

With the scale model, a number of tests with a counter weight of 5kg have been carried out in wind speeds of 20-22 knots. This is actually quite demanding, because the scale model only has one rudder as control. It goes without saying that we crashed the scale model a couple of times, but that is not really a problem. 

What is more, the first steps toward building a real boat are underway. The decision has been made to buil a one person boat first. There are several reasons for this decision. One is that it was much easier to obtain a complete rig for a one person boat. Such a rig only needs to be about 12,5 m2 and is available off the shelf. We purchased a Gaastra Vapor 12.5 m2. A two-person rig would need to be about 24m2 and would need to be developed from scratch. The same applies for the foils. For a one person boat, the foils can be purchsed off the shelf.

Another reason is the financial aspect. A one person boat is more cost-effective and still providea a good opportunity to show the speed potential of the boat. It will be fully functional. 

Moreover, it is to be expected that after the boat is completed, the subsequent testing will bring further insights which would require further modifications. This is also much simpler and more affordable in a one person boat. 

In any case the rig has been bought and modified so that it can be supported by the mast. We expect to start building the frame and finboxes in October 2016. The Dutch company Assemblae is willing to partner with us in building the frame. 

Once the frame and finboxes are finished and tested for strength and stiffness, we can also test the rig and the turning procedure. 

Next, the boards can be made. Flikkaboards is willing to make the boards on our specification. Perhaps the first boat can be on the water in about a year. 

Looking forward to it! There will probably be many challenges aong the way, but that is part of the fun. 




speed trials december 2014


The drama unfolding at the Volvo Ocean Race has been captivating. First, the grounding of Vestas, with the Dutch navigator Wouter Verbraak being responsible.

Next, the great victory of Brunel, a largely Dutch team, in Dubai. Skipper Bouwe Bekking did a great job. Rock bottom (literally) and sky high for the Dutch in a very short time span.

As for Wiebel, we haven't published much lately, but that doesn't mean nothing is happening. The scale model has been upgraded in the last few months. The frame of the earlier model had too much torsion, so the entire frame was rebuilt on the basis of stronger beams. The fin boxes were also rebuilt. The stays were also modified.

The boom was replaced by a simpler one, as the original boom experienced fatigue. The sail was also tuned again. The rudder was slightly modified. The rail was removed for the time being, in order to keep the boat simple. The rail will be re-installed later on.

All in all, the boat has become substantially stronger, especially on torsion stiffness. This was necessary, because in order to go faster, the counter weight needs to be increased, and the frame needs to be able to carry the greater counter weight without excessive deformation.

The boat now weighs about 3kg, and the counter weight was also 3 kg. The sail measures about 1 m2. We therefore currently have about 6 kg per square meter. The world records of Antoine Albeau and Finian Maynard have been set with over 20 kg per square meter, so we still have some way to go, even if it just a scale model. Nonetheless, the boat is improving.

We tested the boat yesterday. The wind was allright, but not great. The video is provided below. It can be seen that the frame is more stable than before. The top speed is about the same as in the earlier videos, but since the boat is heavier and the wind was not great, that is an improvement. The boat came out of the test fully intact, which is the first time. We are therefore improving in the reliability department as well.

The boat also does not make any nose dives anymore. That is perhaps the biggest improvement. In terms of safety for the sailor, it is essential to prevent nose dives.

It remains quite difficult to sail with only the rudder under control and everything else fixed. Simple to construct, but difficult to sail. Therefore, in the video the boat changes in speed quite often, depending on the right airflow or not. The speed bursts are relevant for further developments.

The sail is mounted a bit too high. Funny how difficult it is to mount it low enough to "close the gap".

At 00:29 there is a splash behind the boat. Apparently the frame has hit a wave. This is an indication that the boat may be too low. We may need to increase the height.

At 00:34 the boat hits the bottom, and the leeside comes out of the water. It looks funny, but no damage was done. The testing was perforned at Makkum, The Netherlands, and some areas are extremely shallow.

We hope to be testing in good wind conditions soon to push the speed envelope.

We are gradually making progress on the full size boat. I hope to discuss that in another blog sometime soon. There is a great belief that it will be substantially faster than the Flying Phantom and other foiling cats, because it is more efficient and better geared for high winds.



New name


Wiebel has decided to change its name. The most important reason is that Dutch people do not like the name Wiebel very much.

We aim to attract a sponsor. Although we have an international ambition, that sponsor may be a Dutch party. For that reason we need a name which is liked by Dutch people more than the name Wiebel.

Currently, we are holding a crowdsourcing project for a new name on Nameforce. 

Check it out at http://www.namingforce.com/contest/7335/. If you have a good name, make sure to submit the name, there is money to be won.

More than a 1000 names have already been submitted. Some are quite good. Somebody submitted "sail rocket". Hmm, I don't know about that one.

Whatever the new name will become, we will be  "formerly known as Wiebel".


Walter Hart 

Complete design of the boat


In recent months, the boat has gotten a more definite form.

C-class ?


We just posted another video of a recent test. As is clear, the development of Wiebel is progressing steadily. We are currently making the first arrangements for a full size boat. One of the main questions is: how big should the boat become? Interestingly, the C-class catamarans is a box rule class.


Changing tack


There has been some confusion on the way Wiebel changes tack.

Developing the scale model


Although the scale model on the video works quite good, it is nowhere near perfect.

Planing or foiling


A big issue in speedsailing is the discussion on planing vs foiling.  AC72 for instance now revolves around L-foils. Moths likewise. From this, it appears that foiling is faster than planing.Then again, kitesurfers,windsurfers and speed boats generally plane instead of foil. So what is faster, planing or foiling?