I tried some serious speed runs with my Hobie 16 last weekend and managed to reach 22.4 knots (25.7 mph) in flat water and winds around 20 knots. I tooks us 10 speed runs with double trapeze (150 kg, 330 lbs) and standing as far back as possible. Weather rudder lifted clear, lots of downhaul and traveller all the way out on the jib and 0.7 meters out on the main. We sailed the boat deeper and deeper on the reach, double trapezing with weather hull just touching the water. I was a bit nervous about doing a pitchpole in that speed, but what the heck! We had a couple of near misses where the hull dug in, the boat stopped a bit, dumped the main and we ended up in a pile at the main beam. My crew hit the corner casting quite hard but he felt ok until I landed on him, then it was PAIN!

To get some REAL data out of this I used a software called gpsActionreplay to get statistics from the gps tracks.

Best 500 meter run was 20.5 knots
Best 250 meter run was 21.3 knots
Best 100 meter run was 24 knots (probably some glitch)

Check the link below for the html that the software generated.

http://www.webbo.dyndns.org/hobbe/speed_test/


/hakan

Hakan



This qualifies for the Y+Y Speedfreaks comp.

There is a link there to enter.

Those speeds I can believe, if you are holding them for the long of a run it factors out the gps error.

Cool data!

Wow, I dont think I would want to think about pitching at that speed (24 kts). Keep the data coming Hakan, seems like very cool software, now all you need are a bunch of cameras mounted all over the place, (masthead, bridle, stern, boom, helmet cams) video from that speed would be very cool.

Hakan,

Did you filter out any GPS anomalies from the data set prior to calculating the runs? The Action Reply website discusses how to do this.

I'm suspicous of your posted speeds. All it would take is one data point 30+ knot glitch (which occur frequently with GPS) to skew the averaging computation heavily.

Best I've managed to capture so far on my Tornado is just under 22 kts.

If you want to have the most accurate GPS speed measurement get one of these: Navi/Amaryllo GPS.
In addition to the classic way of calculating speed they make use of the Doppler effect to get the most accurate result (0.1 accuracy).
(This is what the speed windsurfers will use from 2008 onwards).

The sampling time between each tracklogg is 10 sek, and when checking the data in Oziexplorer it was rather clean. I had the gps mounted on the lifewest, not on the arm, to keep it steady. Sheeting with an arm mounted gps is a good way to get speed glitches.
The 250 meter and 500 meter runs feels reliable but the 100 meters are too short based on the tracklogg sampling rate. The gps said that the highest recorded speed was 22.4, but I think it's safer to refer to the best 250 meter run at 21.3 knots.

The highest speed I recorded with the A-class is 20.5 knots using the spi in high winds and flat water trapezing with chickenline as far back as the hull stretches, and that's the gps instantanious speed!
If I analyze that tracklogg from the A-class run using the software I get the following data:
Best 250 meters run, 19.9 knots
Best 500 meters run, 19.2 knots

The Hobie 16 rocks!!!!! It has higher top speed than my A-class, which was something else than an A-class since I was using a spi on it.

/hakan

yeah, but your A was probably sailing almost straight downwind! Try that with the 16.

With a 16 m2 spi on the A-class I sail 30 deg from straight downwind course even though I'm hanging flat out on the trapeze (in high winds and flat water). The Hobie 16 wouldn't have a chance....



The image above is a tracklogg from an upwind/downwind leg with the A-class using spi, wind is from south. Check the angles between the gybes!
/hakan

At the risk of showing my intelectual challenges I have been thinking of creating a special rig for speed runs. It would use a well shortened mast on a Tiger Shark...these boats have hard chined flat, plaining hulls. I have sailed at what I believe to be well over 20 knots on one and not been in the least worried about what it might do re pitching etc.
The idea being that at high wind speed the big rigs need to be feathered and played with to much. A smaller rig keeps centre of effort lower and has much less luffed sail creating drag.
I am reminded of watcing high quality Tornado sailors at a speedweek and they were struggling constantly with boat trim and end up flipping the boat.
My old Attunga..pictured was tracked at steady 38 kilometres and had lots more left in it hull wise. It had no traveller and I did not know many of the ricks I now have to keep a boat calm at speed but it did have over wide, very flat sterns and short eliptical rudders.
To the degree I have been talking about the smaller H14 with spinny lifting its bows might allow a person to be braver and get away with it.

It is a tough thing for many people to get to a speed week. Why don't we create an informal speed rule here and give people a chance to work on outright speed and post results?

Very nice results Hakan! Going 500 meters at 20 knots on a Hobie 16 is VERY fast.

Simply, take the average speed over 500 meters from a GPS track log with at least a sampling rate of onces every 10 seconds (or faster). Calculate the average speed by deviding the distance covered by the time taken. DO NOT calculate average speed by summing all the individual speed averages and then deviding it by the number of samples. The latter can be much less accurate.

The track itself and the series of data points must be presented as proof. Also two runs most be made on opposite tack were the slower one of the two is presented. This to take out surface currents.

Everybody with a simple GPS logger can do this. 500 meter will take a shy 50 seconds to cover at 20 knots. This is sufficiently long to take out riding off waves or other effects.

Wouter

Over the years I have done some beam reaching drag racing against the H16's while sailing a Hobie Tiger and a Formula 16 myself; often in big wind. Each time the boats stayed very close to one another and it always was an inmense effort just to pass the Hobie 16's. When I sailed a Hobie 16 myself I found the exact same thing. Basically, the Hobie 16 is a fast reacher and it always has been.

I'm not surprised it hits 20 knots in such conditions.

Wouter

I mentioned here somewhere that I thought I knew a boat that would be quick in outright speed on a reach. I believe that planing hulls are very important for up wind as well as reaching and work must be done on all cats to achieve this.
I mentioned that Having watched the Tornado video setting 22 knots showed it to be too unruley to set a very high speed.
To put my money where my mouth is I have bought this boat today.
It is a Tiger Shark. The follow up by Ron Given to his Paper Tiger.
18 feet. They came with a 28 and or 30 foot mast. It is hard chined, foam core and has almost flat V sterns.
I have a spare mast and am going to cut one down by maybe four feet. Basically a mast head rig. I thought to rake the mast excessively like the H16 and start from there, work on a lower centre of effort and not have a lot of luffed sail and extra mast to deal with in higher end wind.
I will cut down a spare set of daggers to set and forget.
Any other ideas appreciated.

This is not to make any kind of an all round boat....just reaching outright speed.

Are you gonna change the name?

Don't like it??? I thought I might call it
"Death Slash Devil Slit Killer Kill kill kill!" : )

How did you pull that off? Didn't close till Sunday! Had my eye on it as well :-).

Brings back memories. Certainly a fast boat.

I could tell you...but then I'd have to....

Warbird, I see this is back on the market. What's the story?

You didn't buy that Tornado did you?!

Mark.