International Canoe(DC) SPEED

From the International Canoe forum:
" DC AUS 21 '21st Century Hollow Log' update
By Phil Stevenson 18 September 2006
I sailed the course with the foil Moths this Saturday. Not top line boats but three competant sailors doing pretty well. I was considerably faster in 10kts up wind and downwind but as the wind increased, they went a lot faster downwind and balanced out my windward advantage.(The top sailors would be faster in lighter winds, that being harder to master) I am not sure I would be
as fast upwind as the top foil boats but must be in the ball park."
Phil won his first big race in this boat a couple of weeks ago and this sounds like the boat has very impressive speed! The new "DC" proposed
by Steve Clark seems to be an improvement....
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International Canoe Forum - Designing to Steve Clark's proposed new rules
Address:http://www.intcanoe.org/forum/topic....10&whichpage=8
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Excellent, very informative article on building this boat:
Building a stressed ply Development Rule International Canoe Hull
Address:http://www.internationalcanoe.yachti...52F13920%252F0

[casavecchia]

Having built a Moth hull to his deign, I must say that Phil certainly has a knack for developable surfaces. Being a boatbuilder in wood myself, I really like the compounded plywood method.
Marco.

[frosh]

Phil certainly has a talent for stressed plywood design dinghys. I see no reason why this should not become the mainstream method for building of the new DC's. It is a beautiful, inexpensive sort of low tech. but very clever solution, and very available to home builders with average skills and some prior experience in boatbuilding.
In my opinion, speed comparisons between foiler Moths and DC's are as relevant as speed comparisons between Tornado cats and formula sailboards.
We should not focus on absolute speed under specific conditions as having much importance except in the case of record attempts. Any one who thinks that speed is number one priority misses the whole point of sailing.

[Paul Scott]

frosh-

but why
not? the
ic
was
the bench
mark. it
has
all the goods
to be that
again.

paul (in an ee cummings mood)

[frosh]

Hi Paul, how is your skill on a sailboard? If it is good then get youself a Formula Board with a massively overpowered rig and blast past every monohuller and most multi's as soon as you get planing conditions or more, (around 10 knots) I bet this ends up as exciting as racing cruiser powerboats on your 150 hp. state of the art SeaDoo personal watercraft.
That is the " Because"

[Paul Scott]

Not off topic at all; I'm glad you're agreeing that Formula Boards are one last gasp of the commercial sailboard industry as it exists now. They suck under 8 K, no matter how big the sail, and I've yet to see one go upwind well. Even at the Gorge. I guess if you build to part of the spectrum, you'll do well at that part. The canoe has the potential to do it all.

Paul

[frosh]

Hi Paul, the bit in your last posting about the upwind ability of Formula boards
is patently wrong. I will just quote you first:
QUOTE:
and I've yet to see one go upwind well.

From my personal experience: Around six years ago I was out on my local sailing spot that I was very familiar with, and Formula boards were still fairly much in their infancy; i.e. probably quite a bit slower and less refined than they are today.

I was sailing my Phoenix 340 longboard (early model), which from all reviewers, including the well known sailboard expert Ken Winner, had excellent performance. (He described the phoenix 340 as a mini Mistral Equipe, which was the state of the art course racing board around a decade ago). I also had a fully cambered racing sail, which was state of the art at the time, and full carbon mast.

Now, I am no national champion, but am definitely no slouch, and was very familiar with my equipment and was sailing it fully powered up, in about 18 knots of wind. I was travelling at an optimum upwind angle the with hull railing beautifully and semi planing/slicing through the water really well.

Then I glance behind me, and then I saw this really wide board coming right up my tail but still about 50 metres behind me. I think to myself that I will make him eat my dust, as I had a centreboard, fully down, and was going what I thought was really quick. He I could see had a little more sail area, and no centreboard at all.

A few moments later, I glance around again, and he is now about 10 metres behind me and about 5 metres higher than my course, and I estimate that his angle into the wind probably being around 7-10 degrees closer than mine.

Within seconds of this second observation, my "Competitor" had planed past me, now around 10 metres more upwind than my position, and rapidly leaving me for dead.

That was my first close up encounter with a Formula board, and have to tell you that they really move, in planing conditions, whether upwind or down.
That day was quite humiliating for me!

[Paul Scott]

Frosh-

Phoenix 340 was/is a cool board. And you're right Formulas do go ok in LOTS of wind. I think HyperTech (?) had a skinnier, smaller board that SMOKED the Formulas upwind in the big stuff. The size of it's skeg was AMAZING. I think you should, after a certain point, dispense with the centerboard (but when?) to go really fast upwind. And at that point will you really be going slow enough upwind to need the kind of width the Formulas need to plane?

The idea of only needing a skeg to get upwind well in heavy airs lead me to the idea of using just the rudder upwind on a DC IF you could bring the rig back over the rudder and get the seat back enough. The leverage of the seat and span of the rig, seems to me, would kick windsurfer butt. Bethwaite might even agree.
I think everybody who has sailed a windsurfer has noticed that when the centerboard is fully retracted it's like being shot out of a cannon.

DC 16' by max width? Flat bottom? Boxy Rails? Una rig?

Paul

[frosh]

Hi Paul, there are still major flaws in your contention that a DC could be designed to go anywhere close the speed of a formula board around a triangle race course.
The first is the power to weight ratio: Lets say DC 50kg plus sailor 75kg comes to 125 kg and 10.8 sq. m of sail area in una rig. Say power to weight of 86.
The Formula board 14Kg plus sailor 75kg comes to 89 kg and 12 sq m of sail.
Power to weight is 134.
The other factor is the freesail rig. I won't go into the details now as it is too lengthy but the canting ability, fully cambered leading edge etc. makes its efficicency incomparable!

I regard Phil Stevo's comments with the utmost respect as I do Rohan Veal's. Rohan has said that he's beaten Formula boards in 8-15 knots with the Moth Foiler. Phil has said that he may be equal to the speed of a Moth Foiler in 10 knots or so. If that is the case the DC stands a good chance of being faster than a Formula board in some conditions based on actual on the water experience.
The verdict is still out but the experience of these guys may well portend the future.....

[CT 249]

There's no doubt whatsoever that the DC will be faster than a FW board in some conditions. A Sabot or Opti can give a Formula board a good kicking in some conditions.

The situation according to Rohan 13 months ago was that he was as fast as a FW board upwind but slower downwind. I think (but I'm not sure) he was trialling against Martin who says he's not very competitive in FW. The gap between the top and average FW sailor is vast and therefore that must be taken into account. I don't think there's a single world class FW sailor in Victoria (with respect to them) and the difference between the Vicwegians and a former FW world champ is (I understand) vast. A good sailor on the original Windsurfer One Design can beat several of the guys on the local FW circuit at times, and the One Design is only about as fast as a Laser.

As of a week ago, one of the FW sailors who regularly race the foiler Moths at Botany Bay said that the Moths are quicker upwind but not as fast all round in planing/foiling conditions, I think.

Frosh, the leading edge of the Moth rig (now used in DCs) is basically identical to the board rigs (according to AMAC from KA Sails). The canting rig is always a complex one....Lars Kleppich when coaching says to keep the rig upright, some of the world class FW sailors hang onto the uphaul to keep the rig as upright as possible, the old Wondsurfer One Design likes as much lean as it can get.....all very hard to figure out.

The FW boards really are very impressive in the right conditions. Lechners and Raceboards give seahuggers and Canoes a good old kicking in a bit of wind but the longboards can't really look at the FW gear upwind or down in steady 10-20.

Of course, put them on a narrow waterway or in 7 knots and everything changes, and the FW boards live in fear of Sabots while the longboards are still doing okay.

[Paul Scott]

frosh-

It would be fun to find out though? Couple of things-

The FW rig is flopping all over the place; in an efficient way of course, but has to be really bendy because the pilot's weight is not out very far, so how much power is there really in the sail in the big stuff, where because of the seat leverage, the rig of the DC is going to be really loaded up...?

Like I said, would be fun to find out. As far as SA/Disp, the record setting boards are pretty high and rigs are pretty loaded up. How loaded up are the FW rigs? But you said Power/Weight ratio. Define? And please, get into the details of the rig.

CT- I really like the relativity of your response. Must admit I think that way too.

Paul

[frosh]

Quite a few years ago when really big FW sails 10 sq.m plus arrived and they got rigged up on the beach with so much downhaul that the upper two-thirds looked like it was so incredibly loose, folded and useless looking. With my background in both racing dinghies and slalom type sailboards with smallish sails I was almost certain that the FW huge sail was some major type of mistake.
However out on the water the leverage of the wide board and massive fin, had produced a significant lateral bend in the top half of the mast, and the sail powered up looked like a rigid but very twisted-off wing; really fantastic.
I have witnessed Gaastra pros testing prototype sails mid-week, just two guys on identical boards with slightly different sails. At my local spot 18-20 knots steady sea breezes are typical. These guys actually shocked me as they appeared to be doing powerboat type speeds. I concur with CT that the difference between an average sailor and world class guy (we have a multi world champ living in Perth) is extremely significant, I would say unlike the differences seen in any other type of sailcraft.
Comparisons then between Foilers and FW can only have some validity when it is the champions in each respective class, racing one on one.

[Paul Scott]

I'd really like to understand how FW (say the Gaastra) sails are dealing with twist induced drag. Mr. Speer has mentioned it a few times, but I can't say I understand it very well.

Frosh- do you have any feeling for how loaded up the 10sq FW are?

Paul