High-Speed Sailing

Vessel Name: Sailien
Vessel Make/Model: Experimental/custom
Recent Blog Posts
28 September 2013

The America’s Cup

I watched, with interest, the videos of the 34th America’s Cup. At last we have fast sailboats engaged in a competition that is fun to watch. The virtual images (such as course boundaries, distance grid lines, separation between boats, etc.) overlaid on the real images really helps to keep the race [...]

31 August 2013

100 Knots for Hydroptere?

The latest news from Hydroptere is that they have plans for a 100 knot sailboat. This was posted on 26 Aug 2013, so look for that date at this address. http://hydroptere.com/en/the-news/last-news/

17 November 2012

Aptly named Sailrocket, blasts off!

While yet to be ratified, Sailrocket posted an average speed over 500 meters of 59 knots. I will not be surprised if they increase their record into the 60 knot range during this record attempt.

02 January 2012

More drag for VSR2?

I want to start by pointing out that the whole VSR2 team has done a stellar job and has demonstrated conclusively that the forces that drive a sailboat can be aligned for roll stability without using ballast and without using any down-force. (Trifoiler achieved roll stability by using down-force, but [...]

18 December 2011

My analysis of Sailrocket

I copied a diagram of VSR2 (wing doesn’t show well) and added in the major force arrows that apply. Be aware that these arrows are not correct in terms of scale (length) and some of their locations are guesses, however I believe I’m correct enough for us to learn something about what VSR2 has been [...]

23 October 2011

60 is within reach, what’s next?

I have been watching Sailrocket’s progress with great interest and there’s no question they have a winner. I fully expect to see them reach 60kt in the near future. Sailrocket has now demonstrated what I first learned with my models and again with my full-sized prototypes, that if you get the forces [...]

Wind surfers and Kite sailors

29 April 2008
Wind surfers and Kite sailors are a big part of the speed-sailing picture. At the start of windsurfing (late 60's), sail-boards were essentially the slowest "sailboats" in the water. But by the 1980's they were the fastest. I attribute this primarily to two factors: 1) Sailboards are very inexpensive (for a sailboat). 2) They became very popular. Notice that I omitted technical merit as a main factor.

Because of their popularity and accessibility to anyone (price) the manufacturers made money and superior performance was seen as a way to sell more product. Top sailors were paid (pros) and some real talent got involved with R&D, which resulted in better equipment. A lot of sailors spending a lot of time sailing and raising their skill level, along with better equipment, resulted in a lot of speed.

Notice that in my second post I stated: "Stability of the craft is the single biggest barrier to high speed sailing." And yet a sailboard is the most unstable sailboat in the water. Looks like my statement is totally contradicted by the facts! (Any of you want to place bets as to whether I'll be able to get out of this? I always did like to live dangerously...)

Here goes: The most important factor in the speeds the windsurfers are posting is the skill of the sailor. It's true they do need good equipment but there are only a few that can run at record speeds. The sailor must balance the craft precisely and hold it at max power to do a really fast run. In this case the stability that I said was so essential is achieved by the skill of the sailor and when that stability falters? Wipe-out!

For those of you that think a "real" sailboat should hold the record, be aware that you are up against numbers, not only number of sailors but number of years that has gone into the development of that one type of craft.

Does this mean that I think the wind surfers will continue to dominate? No I do not; they can be easily beaten with the right technology. "Hey Bob, what's the right technology and how can you be so sure." To which I reply, "I already developed it." And you say, "Prove it." And I reply "Show me the money."

I've been working along for a number of years on a minus budget, but I've got all the major factors for a really fast sailboat resolved with my prototypes. I'm looking for commercial, as well as all-out speed interest. (End commercial)

I've seen data that show that at the low end of a windsurfers speed range (true wind under 20 knots) a windsurfer can run at close to 2X the true wind speed. The same data showed that as the velocity picked up the efficiency fell off. This makes sense of course and will be true for all sailboats, since the drag increases as the square of the velocity. Be aware that the skipper of a windsurfer is not aerodynamically shaped and compared to the size of the craft is a huge aero drag. The only solution to this is either sail in a foiled envelop or sail in more wind. I'm sure the only reason the windsurfers have been on top is they've been able to sail in strong winds.

Kite sailors have the same problem. I believe they are also unable to point as close to the wind as a windsurfer, which means they'll have to have more wind to make up the difference.

My view on this is that with the exception of Yellow Pages "brute force" has been dominating. I believe "finesse" can easily surpass brute force. "Stay tuned"

Bob
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