Foiling M20?!

If they are level, then heck yeah those are pretty long boards. Pretty cool to see the development going on.

Cool stuff. Wonder where we will be in 10 years.. Good to see that Marstrøm still work on/for small cats. I bet it will be a handful to make that work reliably and predictably. <img src="<>/grin.gif" alt="grin" title="grin" height="15" width="15" />

Thanks Håkan

This boat needs small symetrical section T or L foils in the rudders.
When the main foils lift the bow, the symetrical section rudder foils lift the transom taking the hull out of the water. When the boat assumes a bow down attitude, the symetrical section rudder foils help keep the transom in the water.

T or L shaped rudders will make things more stable and has the potential to lift the boat in a more controlled manner but will it be faster? The C-class the foiling boat was slower that the

normal boats

.

/hakan

Not in light winds, but they increase the top speed. The new 35ft hydroptere.ch will use a similar setup.

Definitely need to be able to balance the boat so it is parallel to the water when foiling. Means adjustable AOA on the centreboards. Max lift when not foiling, and less lift when foiling as the increased speed keeps the boat up and out of the water.

Deeper rudders are necessary to ensure you can still steer and these don't ventilate by the hull rising up. T or L on the bottom means they act similar to the tail on the plane by ensuring the pitch of the boat is kept into line and you should be able to adjust this angle.

Moths lift at 7-8 knots of breeze, so more development can be done to bring this down on the M20. A huge amount of drag to have in conditions when not foiling.

Maybe they are first developing lifting boards then work on the rudders, makes sense to me. Get the boat to lift off then control the attitude, one step at a time. This could be awesome.

Maybe, but you do a lot of damage along the way. If the main foils lift, and then ventilate at speed (ie instantly loss all lift), then the whole nosedive is a helluva lot quicker. Mainly because the hulls are pointing downwards and then hit the water. Done that many many many times on the moth. The whole nosedive cartwheel experience a lot quicker than i have ever experienced on a cat.

I was under the impression the curved boards were not at all designed intended for full on foiling, rather for a smaller amount of lift to keep it from pitch polling going downwind?

There was a discussion about these curved boards some months ago on the A Cat Forum. I thought they said it was about stability and lift going downwind, not full foiling.

I can't say for sure, but the boards on the A's, M20 and CFR type boats are WELL aft of a boat like the N20. I can't see them adding any lift to the bows.

If the goal is fore and aft stability, the foils should be placed forward of the main beam/mast and the rudder should be deeper. I would have chosen the ARC 20 configuration for experiments, with larger beams, overpowered and in carbon, if possible.

Was this just a test, or do they plan on developing these new and longer boards. Im all for curved boards, but not ones with this much

performance enhancing

ability. While we are at it, lets do some blood doping too!

I don't understand your point there. I want development of new systems, rigs, daggerboard, sail, anything that can make our boats go faster.

I don't see the relationship between this and doping. At all. One is development, the other is cheating.

And frankly if in 5 years we have a foiling cat class I'll probably start thinking about migrating to it. I hope to get an existing class to allow foiling first, but given the current restrictions on curved boards in the F16 and A class I'm less than hopeful on that front, both blew it by changing their box rules to effectively end any attempt at foiling.

Foiling is awesome. I've been a passenger on a trifoiler once and that thing was a hoot. I watch the foiling moth with envy, but I know I'm too heavy for those, and I don't like the idea of spending my sailing sessions swimming. So I'm eagerly awaiting for someone to build a foiling cat for a reasonable cost we can create a class of.

Bannana boards can get very messy if you fly the hull too high as the Canadian C Class guys found out. When the windward hull flew too high, the leeward hull jumped completly out of the water and sent them crashing backwards into the tide. Luckly the boat did not capsize on top of them.

Article here - http://www.sailinganarchy.com/fringe/2006/banana_boards.php

Pepin, not sure if you have followed the A Class vote a couple months ago, but there were some serious restrictions about length and other constraints. Im not saying that foiling is cheating, but its gone a bit beyond the premise of the curved boards intent(at least for the A Class)
If you want to foil, put some of those babies on your 5.2 and start your own class, but dont bring them into the A Class, we want something more

traditional

.

My last post sounded a little harsh, didnt mean it that way!

Wow, looking at that C class cat pictured above, it is amazing to me that one skinny little board can cause that much lift, to lift the entire boat out of the water!

Are we sure there wasn't some other factor, like a puff just died while they were going fast, and they T bagged and that caused the lee hull to jump up so high?

What does a C class cat weigh these days?

That's where I'm confused. If you want something traditional, why are you on a A class? The A class doesn't strike me as a traditional class, but as a development class, like the moth. The moth would be completely irrelevant if they had gone the traditional way instead of embracing something new and exciting...

And I don't want yet another foiling frankenboat, I'd like something based on a modern platform, with a chance to become a class. So the 5.2 is out as a foiling platform IMHO.

I'm not a A class sailor, but I truly believe the class vote to outlaw foiling was a setback.

you dont have to buy the $2000(not installed) boards!

The A Cat is a developement boat, rigid sails, curved boards, carbon everything, but....they drew the line with foiling. Why? Im sure cost is a factor, but bringing the A Cat to a true foiler would really make alot of boats obsolete. A big percentage of A Catters are sailing on older platforms, probably enough to sway the vote to keep it a more

traditional developement class

.
Comparing it to the Moth's probably not fair, at least in the US the Moth is not a very widely raced boat, so therefore stepping it up a notch probably didnt limit alot of boats(at least here in the US)

But is full foiling actually faster?
They used them on the C-Class right?

Full foiling way faster. On the moth the F16 cats in Singapore can't keep up. Passed them to leeward going upwind, and downwind going faster and lower. And the moth only has an 8 sq m sail...

And as for costs of the foils, on the Bladerider and Mach2 the foils and the foil set up contribute to half the cost of the boat (retail is US$14k-$17k). Adding that cost onto the current price of the A would mark things out of reach for an already successful class. Plus the current A class masts couldn't withstand more than a couple of crashes from foil ventilation as you certainly hit the piss hard when crashing.

What I meant was a setback for the development of foiling in beachcats. Not a setback for the A class.

Dave Carlson has a foiling A cat, I think its been around for awhile. Take alook at his Avatar

I think foiling is a dead end for cats, but I love to see people tinkering with it trying to make the technology work well around the course in a cat configuration. If somebody makes it work well enough to beat a Tornado around the course, I would say

lets go!

. Preferably with the current aesthetic looks.

Reason I think it is a dead end: Power to weight ratio is not large enough on the common beachcat to give best performance around a course. (I am very narrow minded, thinking about racing only, I admit that)

I have heard anectdotes like taipanfc gives about moth speeds relative to cats, but I have still not heard about a

grugde match

where moths were faster around the course. I dont doubt that the moths can be faster, just never seen any non-biased reports of top moth sailors racing top cat sailors on the Tornado or similar and beating the T? Or M20 or any similar really high-perf racing cat.

Certainly agree about the Moth, the one at our club when he has come out to play, seems to go off on his own after a short while. I think they maybe faster in a very narrow band of wind speed but that is a very narrow band.

Sailing is all about all conditions and not ideal conditions, not sure the foiling Moth is in the

all conditions

club just yet. I'm sure though with more and more foilers about, we are getting a lot of development from a lot of people and not just a few as has been the case and consequently the foilers can only get much better all round boats. <img src="<>/cool.gif" alt="cool" title="cool" height="15" width="15" />

Moths and Cats are very much opposite in terms of how they (Currently) go fast

Moths - reduce ALL drag as much as possible; very light boats, flat sails, and foil to reduce water drag by flying. Current Moth trends are to more aero efficieint boats; suggestions that more speed will be found by using different foils for different wind speeds (Big foils to fly in lighter wind and small foils to fly more efficiently in bigger winds - do not need so much lift as you WILL have more speed, thus smaller foils, thus faster as less form drag)

Cats - Long thin hulls - so

normal form drag rules do not apply

. Wide boats to gain rightling momentand so more power and so drive boat fast.

Now, my thoughts are documented on how we COULD make cats faster (opposing foils to create RM).

How might we develop cats to foil without using opposing foils?

1, boats need to be LIGHT to remove drag from creating loads of lift to fly -> Small boats
2, boats need LOW air from drag -> small boats
3, once a boat is flying, we need a low drag (and low power) rig as form drag is low, thus as we do not need lots of power, we do not need lots of RM to control it ->Thin boat once airborne as less aero drag
4, as we do not need lots of power once foiling, we do not need wide (and so draggy) boats ONCE FOILING, but we need a boat that can create RM when needed, but have low form drag when flying - We need wings!
5, Small, not very wide boat, but with wings to create RM when needed = MOTH!

IMO, the Moth IS is

dinghy

solution to foiling. Cats will ALWAYS have MORE form drag. Could we design a boat that was low drag (but never as low as a Moth), that thus had more power that can be used.... I'm not sure.

My view is that the way to make cats considerably faster is to create RM as per

Blue Arrow

with opposing foils mounted mid hull to create RM and thus allow huge power to be carried.

One issue with the moth is that currently they foil in about 8kts true. below this they are dog slow, above this they are VERY quick.

The development for the A-class is limited due to the box rule where the tip distance must be at least 1.5 meter. The curved boards on the A-class could probably make a jump when you get close to 20 knots of speed, but you don't want that....

This is M20 we are talking about, and don't se any reason why they shouldn't use curved board for semi foiling if that proves to be faster. There are no rules for the M20 right now, they use all kinds of rigs and also extra wide boats, so whats the problem if they start to use foils?

I haven't heard about a foiling cat that can beat a non foiling cat of the same size around a upwind/downwind track. For pure top speed a Tornado on foils has proved to be faster than a non foiling Tornado.

One of the M20 on Round texel has two centerboard trunk, one for straigt and another one for curved boards, but it turned out to be a light wind regatta so they left the curved boards on the beach.
/hakan

I'll stick to conventional cat design wisdom for as long as moth doesn't show up at an open water distance race, get out through the surf and beat 51% of the cats around the course.

I don't think it will ever happen. Mind you the Australian portsmouth rating for the foiling moth is 20% faster then the non-foling moth but still on a par with the Hobie 16's

'nough said.

Wouter