Karl, I don't understand what you mean by this statement:

>>Honestly just looking at hull shapes compared to the Falcon, (which I did see in person a couple of weeks ago), the FXone still has a better shape to it, but that is from the eyes of a casual observer/potential buyer/admittedly biased opinion. She's got a fat butt in comparison, and weight does mean a hell of alot in this sport, especially when its in the realm of 35%.<<

Are you saying the Falcon has a fat butt?

When it comes to all the different hull shapes out there, I try to look at each one as if I designed it, and ask why it's shaped like that. Each is shaped for a specific purpose, so I look at the hull and ask myself, "What wind/water/wave conditions was that designed for? And what will happen when you get into some other type of wind/water/wave conditions?

I think every boat is designed with a "Purpose" in mind. The quest becomes to find the right boat design for your purposes, and not some design that really won't work in your situation. I think all cats I've seen designed in the past 20 years are very "Pretty" to look at, fat butt or no. You just have to decide if that's going to "work" for your situation. Ocean sailing? Lake? 1 up, 2 up, heavy, light, big wind, light air??? All of that should be considered.

"I like big butts and I cannot lie, you other brother's can't deny..."

Sing along Bitches! You KNOW you know the words!

http://www.youtube.com/watch?v=LNQU-tVSuw4


Bye the Way, that is NOT Sir Mix Alot, that is really JC trying to look like Sir Mix Alot. That JC sure can sing though! "Go Freak, Go Freak..."

No the FXone has a fat butt not the Falcon, just in term of weight.

The FX has a ton of volume, and its lower than it is on the Falcon. Another thing that I like about the shape is the top of the FX bow is more rounded then the Falcon, and much more so than the Blades. That's what I was getting at. The truth is that every boat see's a wide variation in conditions, even if you are just a lake sailor, or just an ocean sailor. Conditions overlap. I'm just shooting generalizations. In lighter conditions there's actually too much volume up front, its really hard for a lightweight to get the nose pushed in. But when the wind is up, its a god send. I did manage to pitch it this past weekend with out the kite up going down wind. Should've pulled the boards up, probably never would've happened.

Sorry for the missunderstanding Karl. And I've never seen an FX1 up close so I can't comment on the fat butt, but my wife told me NEVER to say -anything- has a fat butt, so I really can't go there...I'll take your word for it.

If you think the FX1 hull shape is very bouyant then you should try the Stealth for example, I was shocked when I had a sail on the FX1 just how easy it was to get the nose down and I was surprised just how when the nose did go down how it would continue to almost drive itself down, it was a bit of an eye opener to say the least.

A very sexy shape that just doesn't do what is advertised on the tin in my opinion. In saying that is it a good boat, yes definately for its design age, just things have now got better as we understand more things about very flat spinnakers and the forces they impose.

Karl,

You'll be sailing a Viper soon, right? I'd be interested in your thoughts when you get back.

Karl,

Have you ever sailed a Blade or Falcon? I personally disagree with your opinion on the shape of the boats. And I think your opinion is not based upon sailing experience. Personally I have sailed on a FXone (2-up) (and own a Blade) and sailed a couple of times 1up against others.

What you surely will agree on is that in lighter air (up to 10 knots) the Blade (and probably the improved Falcon) is way our of league for the FXOne (1 and 2 up). Even with 2 on the Blade and an FXone solo we gently sail away (up and downwind).

In heavier winds I have only sailed 2up on the FXone with no F16 to compare. My feeling there was that the boat was as challenging as the Blade. I do agree that the FXone will recover more easily from a pitchpole then the Blade due to the hull shape.

You really should get a test ride and feel the difference.

Gill

Guys,

maybe you should really name this threat the FX-1 bashing threat. It is not about the price of the Icat, or what is in the package, it is just silly F16 power branding.
I don't belief that anybody can judge a boat after one time sailing. You need some hours to learn how to trim. Remember how was your first trip on a F16. An you never got the bows under water, right?

Ok. back to the topic. Even without a spi, I think that the 17000EUR is a fair price for an all carbon boat, assuming good equipement and a modern sail. Apart from that, I like the fact that Hobie is renewing it's fleet of performance boats, committing to modern (or different) materials, sailcut and layout (the Pearl has a furled genaker for example). In the long term it is good for all sailors.

Cheers,

Klaus

This is a 100% bash free post (some tcsh might come tough)

I like it when new boats come up. Not all are destined for success but only time and marketing will tell. Fat bottoms make the rocking world go round and everybodys taste is different. I'll go down in the workshop and fit the last planks on panel #7.

I've sailed and raced the FX-one in both setups for close to 75 hours in total and I've spend 2 days tuning and triming so it it felt well balanced (as it had been setup by a H16 sailor before). In fact, I've almost dedicated a total of 4 weeks of sailing in all kinds of conditions over a 18 month time span.

I think that I'm entitled to my honest appraisal.

It isn't like I jumped on it for 5 min and proclaimed that I had sassed it out. I gave it lots of time to proof itself as I was looking to buy one. In the end I just could not bring myself to do so and co-founded the F16 class.

I agree with the others. It has too much volume for 1-up sailing, bows almost always ride out of the water and are doing nothing for you. The mast is very stiff and the daggerboards are too long, this makes for a flighty boat in gusty conditions with only an insufficient 8:1 downhaul that can't really bend the mast enough. It is actually a noticeably better boat when sailed 2-up at about 120-150 kg. And at 85 kg I could not right her unaided (by rescue boat or special righting aids) while I can right my own F16 in all conditions from very light winds to harsh conditions. When comparing dive resistance / recovery then the FX-one wasn't much better then the F16's I've sailed (for less hours then I did the FX-one). The Stealth F16 was by far the best boat in this respect.

And I really don't think that stating ones truly honest evaluation can be marked as bashing. Or am I also bashing the stove when I tell my nephew that placing ones hand in the fire hurts ?

Now again, thew FX-one is not a bad boat in its own right but in comparison to a well designed F16 it is easy to tell where its design can be improved.

Wouter

Hi Wouter,

I didn't quote you and I didn't have you in mind.

Do we still get a fruitful discussion about the design and pricing of the Icat? Many interesting points, like low aspect ratio sail, low mast height (compared to A cats), CFRP hulls...

Cheers,

Klaus

Ohh, my mistake !




If you want ? Of course !

Aspect ratio of the mainsail = 8.1^2/16 = 4.10
Aspect ratio F16's = 8.1^2/15 = 4.37
Aspect ratio F18's = 8.6^2/17 = 4.35
Aspect ratio A's = 8.8^2/13.95 = 5.55

But of more interest are the mast heights

iCat/FX-extreme/FX-one = 8.5 mtr
F16's = 8.5 mtr
F18's = 9.15 mtr
A-cats = 9.10 mtr

From an energetic point of view those 16 sq. mtr. of mainsail on a 8.5 mtr mast do not differ from the 15 sq. mtr. sailarea of the F16's on an equally tall mast. that is what the aspect ratio confirms.

Roughly speaking, both the iCat and F16's will milk the same body of air for energy and there is no reason to believe that the added sq.mtr. on the iCat will milk more. In fact, in lighter winds the airflow will stall more easily on the iCat sail and in big winds the added area will only require more depowering. I for one expect the iCat sail to be as good as the same in performance at both 16 and 15 sq. mtr. Which in my view makes the upgrade to 16 sq. mtr. (and non-F16 compliance) pretty useless.

With respect to CFRP hulls, if the iCat comes out at 220 lbs (ex spi) or higher then the use of carbon is questionable. F16's get down as low as 104 kg with plain alu tubes and GFRP. The added stiffness of the carbon in the hulls and beams will never amount to a significant performance difference. It will feel nicer but that is not the same as being faster.

But more interestingly look at the iCat pics (especially about the sterns):

http://www.hobie-cat.net/img/phototeque/icat/index.html

And then at the Falcon pics (or other F16)

http://www.falconmarinellc.com/falconf16.html


I will tell you where the major difference is between the iCat and the F16's. The iCat has about 230 mm longer sterns behind the rear beam. So making a F16 hull out of the iCat is pretty easy. Just insert a 230 long plug into the mould and move the stern 230 forward while fitting the same rudder stocks.

I've notices the same things when a F16 laid next to a Tiger or FX-one. The bows, the mainbeam location, stays etc are all in the same place. It is just the rearbeam location and the length of the sterns that are different. With regard to the FX-one the rearbeam was pretty much at the same location as the F16 and only the stern was longer by a 230 mm.

Since the keel line at the sterns is pretty horizontal anyway, you can just cut it away without upsetting the balance of the boat significantly. You are not really going to miss those 3 kg of bouyancy. Shifting your weight a little bit more forward will bring the boat back on its waterline again.

So, while trying to be really unbiased, I'm again amazed at how closely the iCat resembles the F16's. I truly amazed as to why Hobie Europe decided to go that route.

Wouter

So Mike and Karl,

You guys may even try to purchase an iCat F16 !

Just order your hulls with the last 230 mm chopped of the sterns. This is less problematic then it sounds !

I wrote 230 mm here (= 9 inches) as that is the hull length measurement of the FX-one and I have as of yet no reason to believe that the iCat hull is longer then the hull of the FX-one.

And then ask for a 15.0 sq. mtr. mainsail and you are ready to go !

Wouter

I guess Hobie will not in a Formula class, if they can avoid it. They like SMOD, the Tiger has its on class in parallel to the F18. That says a lot. Hence I would not only compare against F16...


Opposite: it will stall easier on the smaller sail, since the chord is shorter and hence the Reynoldsnumber is lower. So larger cLmax for the Icat. Furtherore a 16sqm sail with same luff length has 6% more maximum lift due to area. Hence the the Icat has a bit more than 6% additional lift.
Of course it doesnot help beating, but on a run or downwind without spi.


yes and it will have more friction drag, hence lower lift/drag ratio and sail lower when beating.

As well, a CFRP in 9m can still be righted by a single sailor, but they didn't use this advantage, the stay at 8.5m. Which means more induced drag (compared against a A-cat for example), so again lower angle while beating, but less heeling moment. That means it can be sailed with more lift in strong winds. On a run, quite useful again.

All that let me think of a boat which is optimised for a run, rather than for upwind-downwind. So not a racer but a fun boat with a lot of bling bling?

Of course one could simply cut the ends of the hulls, but the volume distribution would be not optimum, apart form the fact that wave drag rises anyway with less length (at same displacement).

Where does the weight number comes from? I would wonder if they achieve only 220lb.

Cheers,

Klaus

A catamaran sail is not an aircraft wing and aspect ratio / Reynolds numbers are only part of the story.

The wider iCat sail will require the airflow flowing over it to contain more energy to overcome the (longer stretch of) negative pressure gradient towards the leech. If this air flow doesn't live up to this requirement then a backflow region will form that will detach part of the flow from the sail surface. This is conceptually very akin to stalling. This is the same reason why full sails are slower then flat sails in light winds. Read up on on this topic in High Performance Sailing by Bethwaite.




Ahh, but have you factored in the energy balance ? Or would you claim that a 150 sq. mtr. sail behind the same 8.1 luff will have 10 times additional lift ? Note that I was talking about light winds right !

When the craft moves at 2.5 m/s then a total area of 5*8.1 = 22.5 sq. mtr is swept for energy (harvesting). The total amount of energy enclosed in the assocated body of flowing air is a finite measure and hence the maximal amount of lift (drive) that can be milked from it is limited as well. My claim is that in light winds the total amount of net energy available for harvesting is the limit to maximal attainable drive and not any secondary measures like sail area as is the case in medium winds. In strong winds the total amount of righting moment is the limit and then too sail area is of negligible importance. So a larger amount of sail area is favoured in mid range winds but not on either the light or strong wind ends. That was my point I wanted to get across in my earlier posting.


Wouter

Yes, but both move through the same medium, the air, which belongs to the same law of physics.


Actually, assuming the Icat sail has the same cp-peak and the same pressure recovery over its longer chord, it will take out more energy of the flow, hence more lift. That's the area effect, bigger sail, more lift. Both sails could start from the same cp-peak, since this is the real physical limit. Both sails will recover the cp to about zero at the trailing edge. However the sail with the longer chord has this pressure gradient over a longer distance, hence less steep, hence more stable, less prone to stalling.



Of course, you cannot take out more energy from the wind as there is in it. However there is plenty of energy, if the wind is blowing constantly in a large area. That's what most people would call favorite sailing conditions. Having just small patches of wind whispering here and there (what you call light wind?) might such a case of limited energy.


There is never a finite volume which is affected, since both the up- and downstream air is affected (even the air above the sail). That follows directly from the principle of conservation of momentum and mass.

Assuming same mast height and luff length, a 16sqm sail will be favored above a 15.5sqm sail on a run or downwind leg.

Cheers,

Klaus

And yet the total energy available for harvesting is finite just the same (my point).

The total sum of 0.3 + 0.03 + 0.003 + 0.0003 + 0.00003 + etc may indeed be infinite in its composition but it final value is not ! Note how the value of the above infinite sum is simply 1/3rd; the quotient of two very much non-infinite numbers.

Look at the bigger picture. God doesn't roll dice and there are no infinite end results in physics. There are only limitations to what the human mind can still comprehent and inaccuracies in our mathematical models.




Unless it encounters another limit that is overlooked. I was never talking about an airflow with sufficient high energy levels, I was talking about light airs; the area were very tall and skinny A-cats sail excel. Now the question to us all is why they do so. It is because they have lower drag coefficients in their sails or because their rigs swep a larger area of moving air and thus tap into a larger volume of available energy ? Note, that as soon as the body of air becomes sufficiently energized they loose much of their advantage.





In fact, the maximal amount you can harvest is significantly lower then that.

Look up the Betz law to get an idea of what kind of limits are at play.




Over all possible conditions ?

I think you will find that there are exceptions.

Wouter

The propulsive power of a saildrive is P=F*v, which is P=0.5*rho*v_appwind^2*v*Ssail*Cn, with Cn as aerodynamic force coefficient, and ssail=lluff*chord
The windenergy is Pw=0.5*mass_air*vwind^2 or Pw=0.5*rho*vwind^2*Acapture*v, with Acapture is the cross section area of the wind affected air mass. A simple but wrong assumption would be 1/4*pi*lufflength^2)
Boat speed v and apparent wind will depend on wind speed vapp^2=vwind^2+v^2.

eta=P/Pwind, with all assumptions take into account leads to:
eta=4/pi*chord*cN/lufflength*(1+(vboat/vwind)^2)

eta must be <1, (the Betz law in only applicable for standing wind power plants, not for moving. Sail are not like wings, but as well not like wind turbines )
anyway we could deduce vboat/vwind = sqrt(lufflength/chord-1). Hence more chord is less speed, which is something what you have in mind, I guess.

Now I make a realty check: I was sailing with my wife on our 14sqm sail area, 8.5m luff length Javelin 16, around 225kg. My friend was sailing his T solo and Uni (around 17.5sqm and 9.x m luff, 230kg). Light winds, we had all difficulties to get the hulls out of the water. As long as we were sailing Uni, we was pretty much the same speed. However once we open our genaker (low luff of about 6m, but lots of chord), we took off and was ways faster. This happend not only one day.

So what is wrong with the theory above? It is the assumption of the capture area, because it depends not on luff length, but on sail area. If I remember right, there is good explaination in "The origins of lift" from Arvel Gentry, somewhere on the internet.


No, in strong winds the adavndage disappears. It is sometimes better, sometimes equal on these courses, but worse when beating. That's way I think Hobie has different customers in mind. More recrational sailors than racers, which are probably the bulk.

Cheers,

Klaus

Read what I actually wrote. I said :

"Look up the Betz law to get an idea of what kind of limits are at play."

I didn't state the Betz law was fully applicable to the sails just that similar limits are at play. Even a sail can not milk 100% of the energy enclosed in the wind as that would mean completely stopping the flow and as we all know, stopping the flow is associated with all kinds of bad effects like stalling.

Other then that I think you quotes of mathematical formula (physics) is confusing, also to yourself. You say :



But this equation is ONLY true when sailing on a beam reach. For upwind sailing and broad reaching you'll need to modify this Theorem of Pythagoras considerably.

I understand what you are trying to get at, but beware of modeling errors. Todays racing sees very little beam reaching and that course is of no significant importance for bouy racing. If the iCat was designed as an optimal reaching boat then it would have had a jib.




What I was getting at was that sail area itself is only of secondary of tertairy importance in the larger picture. Luff length (as that is associated with swept area) and sail shape (large heads) are more significant factors for overall performance, especially in light winds. Therefore I claim that using the same mast length and luff length as the F16's the iCat larger mainsail will at the very best show only very small performance improvements in conditions other then medium winds. As a result, it is questionable if the larger sail will be a factor at all in comparison to the F16's. I truly believe that iCat to be about the same performance with a 15 sq. mtr. sail as with its current 16 sq. mtr. sail although the measurement based rating systems will assign a full hit for the extra 1sq. mtr. anyway.


If I punch in the numbers for the 1-ups + spi in the Texel rating calculator I find the following

Hobie iCat 97.65
Formula 16 100.67

I've used the same data for the iCat as the F16 except for the hull length and mainsail sail area. In answering Karls question. The minimal weight for a spinnaker setup+snuffer is 4.0 kg or more. Typically they are around 5kg therefor the ready to sail weight of the iCat was set at 104 kg = F16 min weight in 1-up mode.

I personally don't see the iCat with the given specs outperforms the F16's by 3 handicap points (108 sec = a shy 2 min. per hour racing). Not when the only differences are a 0.290 mtr longer hull and an added sq. mtr mainsail area behind the same luff.

Wouter

Here are some of the iCat specs Hobie is willing to make public as of yet.

http://www.hobie-cat.net/img/produits/icat_description.pdf


And Klaus




I wonder how many recreational sailors will pop 17.600 Euro's for a boat they are not intending to race anyway. And why none of them would not pop 15.000 Euro's for an extremely similar F16 that in when used in recreational sailing will feel no different then the iCat.

In fact I feel that this particular group of sailors will most likely buy the Nacra 500 at 12.500 Euro's which is actually a very good design with an excellent new suit of modern sails by Performance Sails. The H16 is already at 10.600 Euro's and basically a dog when compared to the Nacra 500. In fact, the Nacra 500 is a hit at my own sailing club. The non-race-oriented guys who used to do Prindle and Hobie's (excl. Tigers) are switching to the Nacra 500.

Wouter

Yep, on Sunday mornings my communication skills are not fully unfold but you managed to get it anyway.


If it is considered as a single hander, not necessarily.


Some people buy simple watches for 15 Euros, other for 300 or 10000 Euros. Because it looks good.


Because there are very few F16 dealers, but many Hobie dealers and many people like after sale service, if they put a lot of bucks on the table.


It depends pretty much where you are, what dealer is there, etc. On our remote beach for example, A-Cats seems to be liked for that as well, somewhere else that are Nacras, Topcats or Swell Shadows (the later is quite comparable to the Icat, not necessary in the dimension or price, but in the target group) or whatever. Hobie missed to offer an adequate product there, and I speculate the Icat could it be.

Cheers,

Klaus