Nacra 52 and Fear Factor

I've been away from the forum for several months now due to moving issues. But in the past a number of N 5.2 racers helped me with many new guy questions. I have kind of a loaded one for all of you with this note. I had a Hobie FX owner tell me that now after a year of single handing it he was getting over his fear of flipping and was comfortable with the boat. I'd never heard anyone be that candid. Which leads to my question. I have lots of experience in monohulls in winds to 25 and have known how to handle the main and jib and traveler so that I never flipped, even after putting a lot of rails in the water. How much of a fear factor is there with the Nacra 5.2 when single handing? Do I need to stay off the water in winds of "X and higher" where I don't know if "X" is 10 mph or 20? If it is any help in your answer - I weight under 170 and the cardiologist says I have only 7 stents in my heart so I should take it just a little easier these days, so I just really don't want to have to handle the "flip it back upright" maneuver if at all possible.

For Jake and the other Nacra 5.2 guys out there that have helped me in the past - I'd appreciate your ideas on this. No sense in my makin a total fool of myself if I can avoid it!

Dick
N5.2 - 3002

Dick,

It sounds like your asking about what wind speed are you more likely to capsize. Previously I've been one of the more capsize prone skippers prior to now simply because I always pushed hard and felt that the easiest way to learn where the limit is, is to exceed it...frequently. I was never concerned about it until a few recent incedents have made me back away from the limit a little and now we're constantly one of the more stable boats on the course (all the sudden we're placing better in the results too...geee...).

Righting the boat, especially if you are trying to do so quickly, can be pretty exhausting but the most tiring part is after the technically difficult one. It becomes physical just as the boat comes upright when you grab for the dolphin striker to keep the boat from rolling back over the other way and then when you try to a) keep the boat from sailing away from you and b) get onboard as quickly as possible to stop the jib from luffing and tearing itself apart. I don't think you can ever depend on not capsizing - freak gusts or rigging or gear failure can hit you at any time and we should all be prepared for it. Barring these kind of failures, I begin to feel a little less in control and a little more at the mercy of the wind when the wind speed gets to about 18 knots. My fun level starts going down from there to where 22 knots is simply not enjoyable and is a struggle to stay upright and keep the loads low on the rigging (like mainsail luffing and mast hoola'ing).

Pretty much it did - my guess was that for my weight and age that I need to either have a crew for extra hands or keep it on the shore if the winds are much over 15 and higher. This past weekend I would have had to single hand in our regatta with winds starting at 15 and running into the 20's with 2 to 3 foot white caps. I opted to watch rather than single hand. I am also presuming that IF I did opt to go out and did some dumping of the main and putting the traveler down like in a monohull that would help in keeping it upright, just like a monohull. I'll stick with your ideas on the wind speeds and I'd already determined that 25 mph means watch the younger guys! LOL! Was good to see you are still helping folks out when I checked back in to the site yesterday.

Dick

Yeah - putting the traveler down and dumping the main are certainly prescribed upwind. In fact, upwind is not really the problem. It's when you are downwind, or transfering frmo upwind to downwind 'though the circle of death' that you become vulnerable. You can only do so much to prevent capsize in nuclear conditions whilst sailing downwind.

I don't understand this fear-of-capsize thing. If you don't want to capsize, it is actually pretty easy not to. When you are racing and pushing the envelope, that's a different story. Maybe capsizing is a guy thing. Personally, as a woman, I try to avoid it.

Pitchpoling is Fun! Can't wait until I get to do it again (seriously)

The fear of capsizing thing comes more so when the cardiologist tells you that you need to limit your physical stress to walking and not running and all that kind of junk. As a life long type A it is hard to give it all up totally, so I acquiess to his demands by making sure I can mostly avoid the trying to right the beast situation. I love speed and all that stuff, I just have to accept that there might be a bigger set of guidelines on what all I can take on than in the past. I'm looking for what that upper end of the Bell curve is without having to go test it to see that indeed it happens! When you get really old like me you too may be forced to accept that you can write the check, but maybe your body can't cash it all the time! LOL!!

I always worry about flipping and having an insulin reaction on the water (even though I've not had one in over 10 years as a type I diabetic)

I've never had a problem keeping my boat pointy-end up for the most part. I did have a freak wind gust auto-gybe me and death-roll me going downwind once, but I should have been doing the wild thing anyways and it wouldn't have mattered.

Live and learn.

Make sure your mast is sealed and you CAN right the boat. If it happens (and you aren't racing) just relax, take your time, once you get it up, just put her in irons for a bit while you collect your thoughts (and your breath). Reverse the rudders, travel in a bit and blast off once again.

The trick is having the confidence in your ability to right the thing. That way when it happens, you don't go into a panic.

Get a boat that is easy to right. (unless you are stuck with that nacra 5.2)

But definately make yourself a rope ladder to make getting back on less strainious.

Hang it off the mast step pin and flip it over the mainbeam when you want the mount the baot again after being thrown.

Simple trick, does the jump, and saves you from doing a second power trick after righting the boat. 50 % reduction in heart failure risk.

Wouter

Thanks, Wouter. You just gave me a good idea for something to make to get back on my boat -- in fact, maybe two or three ideas.

Hello Wouter and Mary,
You should both try climbing back onto a boat with a rope ladder. It is not as easy as you might imagine. What actually happens when you put your feet/foot/weight on a rung down in the water with your upper body against a rigid body like a beam or the side of a hull is that the ladder at your feet moves moves away from you quickly and goes under the hull or beam. Your center of gravity aligns itself with the center of support, the part of the ladder attached to the boat. Your chest and head and arms are located to the outside of the hull and your feet,legs and waist go under the hull. The lower end of the ladder approaches the horrizontal. You can't get vertical lift/push out of a horrizontal ladder. It turns into a mess and a real fight to use a rope ladder in the water. I found it easier to not use the ladder and just climb up on top of the beam/hull as best you can. A rigid ladder works fine, no problems.
Bill
PS How about the drough chute and righting the boat with the mainsail. The righter ends up on top of the tramp at the end of the process. No problem!

N5.2 Dick,

I understand your concern.

I also understand your love of sailing. So, you are asking very logical and open questions.

As for 'the flip', we have all done them. I have flipped in 5 knots of air before also In fact, this was the time the I 17 did not want to right itself! ( not enough wind to lift the sail) When I finnally agreed to have the RC boat assist me, the I 17 just slide on its side,, so it took forever to get the boat up even with powerboat help.( lifting the mast tip did not work either.

Here in the Caribbean, it is trade winds/waves 90% of the day/week/year. That would be 15-20 mph, 2-3 foot waves as normal.

I have not flipped in 2 years, and we sail/race year round. You just have to know the upper limits of your boat. Plus, I see my jib/main friends flip all the time, the Uni is kinder in this respect. In fact, when a knock-down gust come thru the course and the jib/main cats are going down,, I just throttle back knowing, that I will win that race, by just being under control and making it thru the course. I am sure you have all seem this on race day.

Here is another option, on 'big air' days, have a smaller set of sails made , to be used. This is what I did. In the last 20-mph regatta, I used the 'small' sail ( 150 sf) and the boat was a sweetheart at full throttle, never even considered a 'flip' at any time.

So, the best solution, I believe, is to 'out-think' the problem. What can I do to lower the chance of 'flipping'?

regards,
Bruce
St. Croix
USVI
I 17

ps; Is there a jib on your N 5.2? If so, maybe you consider a Uni boat. There are many available now. The F16HP's,F-17, etc. Plus, if you have these 'big winds', you do not need to go spin to have fun, these boats perform great,

Rope ladders are singularly useless, even for kids and tree houses, however us pirates could maybe benefit from the concept: Some people need to use the strength of their legs to climb aboard. Something that allows them to get a foot or knee purchase. How about a "single rung" rope ladder secured so the rung lies along the side of the hull, say at about waterline, when deployed? That way the rung can't get away from you when you attempt to climb. A 2 x 2 wood running board for boats.

Bill, I am completely aware that rope ladders do not work in the water, suspended from the hull or the beam. It is just that Wouter mentioning the word "ladder" made a light bulb go off in my mind -- the answer is not stepping, it is climbing.

I sail a Hobie Wave, which has unique problems. It has no dolphin striker. It has no trapeze handles to get hold of. And it has a lot of freeboard. Even if you have a "step" suspended in the water at the main beam, you have nothing above to get hold of to give you enough leverage to get back onto the boat. You cannot grab the mast high enough to be of help, because the sail is in the way. Women usually are not able to reach the hiking strap, and even if they can, they still do not have the strength or leverage to pull themselves back on the boat at that angle.

So it finally dawned on me that what I need to do is put an eye strap on the front of the mast up about 4 or 5 feet. From that eye strap I can suspend either a narrow rope ladder or a rope with big knots in it -- something to give me the ability to pull myself up onto the boat.

I have always known that I can right my boat easily but that I am totally incapable of getting back aboard after it is righted. I feel better now that I have come up with this solution, which I suppose should have been intuitive.

Next time I sail, I will try it out, just to gain peace of mind about being able to self-rescue myself. It is also comforting to be able to get back on your boat quickly when you are in waters that are infested with either sharks or alligators.

To Bruce and all the others that have given me ideas - thanks. I got this particular Nacra because I know it's history and record. It was purchased new in 1985 by one of our club and he used it for about 9 years to kick everyones butt in our weekly club races. He came in and said "Enough is enough - I flipped for the last time - when ya get to be 74 there are some things you have to stop doing" -- of course that was after he single handed righted it and came back to win that race! He is now 84 and waiting for me to get his boat back on the race course so he can come crew with me!! When I do that I'd just kinda like to do it in a reasonable manner - and all of your comments have helped. At a certain age you realize "out thinking" them has become a major tool!!

Dick
N 5.2 - 3002
Cats Paw

I rig a simple loop in my righting line. It hangs off the front crossbeam near the mast step. Normally the loop would be just under the water. It does not act as a ladder, it is something to push against when you can't quite get back on the boat.

I figured it out on the fly when a "crew" proved not strong enough to climb back on the boat and too heavy to lift.

I had a real eye openning experience a couple of years ago. Out of 34 people at a pool safety course only 2 were able to climb out without the ladder. That is a lot easier than climbing back on a boat

WOW.

After dumping my SuperCat 17 which had no dolphin striker and a big rise to the front beam I needed a way to drag my old fat body aboard when exhausted. I threw the righting line over the bridle where it meets the hull, then tied it off to the mast. The lines hung down as a "hammock" which I could step on while holding on between the the hull and beam. Very successful since my weight was centered over the line.

Now I keep a loop tied in the line by the mast and a carabiner at the right place out the line so I can clip this rig together quickly while swimming. Works great if exhausted.

I think most of us Wave sailors have the loop in our righting lines, but I still need something from above to pull myself up. Rick suggests grabbing the halyard to pull myself up, so I will give that a try, too.

Regarding rope ladders.

I have never tried climbing a rope ladder while in the water, but on land you always have to climb them sideways. Ie. not climb it on the front side like you do with a regular ladder, but 90 degrees to the side. Perhaps this would work in the water as well?

There are 'rope ladders' with aluminium steps, that would sink and not float a bit like regular rope. In technical rock climbing 'rope ladders' are quite common, perhaps something usable could be found cheaply at a climbing store if someone wants to try it out.

Allow myself to introduce my..self.
Have you ever seen a dolphin stand on its tail? Well my getting back on the boat would look just about like that if there were sharks and alligators!

I use a loop in my righting line as a step, but try to keep myself in good enough physical condition to not need it. It is there for times of fatigue and exhaustion.

GARY

Backside-up Easy Boarding: Float under to the back of the cat because it is much lower. The rudders are pushed sideways anyway to stall the boat- so hold them that way! Get inside the tiller crossbar up close to the rear beam to grab a hiking strap. Now get one foot up onto the hull- BEHIND you, as these leg muscles are often stronger. Combine the leg lift with your hiking strap arm to lever yourself onboard- and note your boat arm is now bending the CORRECT way so you can pull yourself over the rear crossbar with biceps.

With your backside UP, you don't have to get your butt so high up this way. Now I'm gonna make my wife try this. HAhahaha

Maybe this needs a video clip- anybody?

We have one of the World's Funniest Videos of a guy who got on at the back of the boat. I think I have told this story before on this forum.

It was a guy and his girlfriend on a Hobie 18 at one of our seminars back in the early 1990's. They capsized, and they managed to right the boat with little difficulty. The girl got back on the boat from up near the front and dutifully started getting the sheets organized and preparing her jib. Meanwhile, the guy swam to the back of the boat and got onto the boat over the back beam.

Now, as we all know, when you go to the back of the boat, the boat tends to turn downwind. So the boat turned downwind, the guy did manage to get onto the boat, but then lost his balance and immediately fell off.

The boat took off downwind with nobody at the helm, and did several wild jibes, with the main flying back and forth across the boat.

Meanwhile, the crew was dutifully looking forward, trying to tend to her jib. It was several "interesting" seconds before she noticed that her skipper was not on the boat. At that point she did the right thing, pushing the tiller over and stopping the boat by turning it into the wind.

And meanwhile, on the coach boat, Rick and I and guest expert Carlton Tucker were laughing hysterically as we went to pluck the embarrassed skipper out of the water.

Afterward, the crew said, "I turned around to reprimand him for not controlling the boat properly, and that is when I noticed that he was not there."

It was funny in the context of a controlled environment, hot weather, very warm water and a coach boat right there; but Carlton pointed out on the videotape that it could have been a very serious situation in cold water and without help nearby.

Sorry, we don't have our blooper videos in a form to show on the forum.

The easiest, safest, least exhausting way that I know of to get back on board any cat after it has been righted, is to position yourself in front of the front beam facing towards the stern of the cat, put both hands, forearms and elbows onto the trampoline with both hands pretty much under your chin. In this position it is relatively easy to raise yourself partially out of the water, at least enough so that you can swing one foot and part of the leg onto the deck of the nearest hull, with one leg on the deck and both arms on the trampoline at the front beam it is then simple (and easy) to bring your other leg also onto the deck. With both legs on the deck and both arms on the trampoline just roll your body backwards onto the trampoline (head facing to the sky) and WALLA success! This has never failed me as a successful way of remounting the "steed" in any weather that I have been able to sail in, and the beauty of it is that it is almost as non strenuous as stepping onto the tramp from off of a landing jetty (only a little more damp) and it matters not whether there is a dolphin striker or just a smooth, plain beam.

darryl,

That doesn't work so well if you have a self tacker mounted to the front beam. I always try to go to the windward side and grab the trap handle to pull myself up. If you go to the leeward side, your body dragging in the water tends to try and pull the boat further downwind.

Now that I have a self tacker too, and had righting practice 3 times the first time out on my Tiger including one turtle, I have been thinking about how to control that better in big air.
I think one person could stay on the front crossbar acting as the drag to keep the boat into the wind and held down. The other person could go up the windward trapeze. Then keep the boat head to wind while the second person does the trapese monkey climb.
It wasn't a problem in flat water and 15, but I have a feeling when the S*&t really hits the fan two people swimming for the side of the boat could let the thing get away.

I can testify to that - two of my friends flipped a Tiger and lost contact with the boat while manouvering around it to get into a righting position. The Tiger threw a pretty reasonable wake as it blew off downwind. We rescued the two drowned rats and delivered them back to the boat - but if we weren't around it could have been more serious....my first priority now is to keep contact with the boat at all times.

Chris.

Those damn self tackers!!!! It has always been my humble opinion that if a cat uses a self tacker then it shouldn't really have a jib!! The entire concept of a self tacker on a cat is to try to make the jib more "automated" and as such tends instead to make it almost superfulous to needs, and more of a liability than an advantage. I have always felt that on a cat that carries a spinnaker the jib gets in the way more often than it helps anyway.
I am sure that there are many sailors with quite contrary views though.

What is the problem with the selftacker ? I seriously fail to see one.

With regard to :

>>as such tends instead to make it almost superfulous to needs, and more of a liability than an advantage. I have always felt that on a cat that carries a spinnaker the jib gets in the way more often than it helps anyway.


I say, bring your boat without a jib and I'll beat you on the upwind leg in such a way that no downwind disadvantage will make up for it.

That is the "liability" of a selftacker

Wouter

As I said, many sailors with contrary views

I thought the jib was only an advantage over a unirig when reaching and that up wind it didn't make much difference.

Going down wind with a spinnaker I'm not sure a self tacking jib makes much difference vs. a uni rig - as the sail area tends to be rather small compared to the main and spin. That said, they also look after themselves when gybing and tacking so I'd rather have one for the all round flexibility when distance racing.

Chris.

>>I thought the jib was only an advantage over a unirig when reaching and that up wind it didn't make much difference.

That dependent on how you define the comparison. And no this is no joke. There are three ways of looking at it :

-1- First is trivial, If both are sailing without a spi then the sloop is definately faster around the course.

-2- The unirig has the same overall sailarea as the main+jib combined of the sloop and both sailing with spis. With the right mast height (not too high) the uni will sail just as fast or slightly faster upwind than a sloop rig. While reaching the roles are reversed.

-3- The uni-rig has a the same sailarea as the mainsail of the sloop and both use spis. Here the sloop is faster upwind, faster on a reach and about as fast on downwind legs.

So the question is from what point are you looking at your boat ?

If you have a boat and want to go faster than removing the jib is not going to help you. That will only make you slower. If you boat is a uni-rig and you have righting moment left unused and want to go faster than putting a jib on is most efficient. At least more efficient than putting a larger mainsail on the same mast. If you are prepared to totally modify the rig than completely new mast and mainsail combo could make you faster around the course if you get the ratio's right. However the gains are dependent on windstrength and you could well find you gained in light air something that you are lacking as a result in heavy air.

No matter how you look at it, one can always put more sailarea on a boat when it is a sloop rig than you can on a uni-rig. On courses that do not require high pointing this means more speed. And on courses that do require high pointing this means that more speed compensates for lower sailed angles to some extend. It dependents on the ratios where the compensation is partially or more than enough to fully compensate.


>>Going down wind with a spinnaker I'm not sure a self tacking jib makes much difference vs. a uni rig - as the sail area tends to be rather small compared to the main and spin.

That seems to be the case.

>>That said, they also look after themselves when gybing and tacking so I'd rather have one for the all round flexibility when distance racing.

And that is where the sloop is best.

Wouter

Hi Wouter

you said:
-1- First is trivial, If both are sailing without a spi then the sloop is definately faster around the course.

my opionin:
If this would be the case, all the A-Cats would carry a gib....

you said:
-2- The unirig has the same overall sailarea as the main+jib combined of the sloop and both sailing with spis. With the right mast height (not too high) the uni will sail just as fast or slightly faster upwind than a sloop rig. While reaching the roles are reversed.

my opinion is
When sailing under gennacker, the gib IMO dosn't do mutch.
I think the Uni will be faster, because with the higher mast, you can hoist a gennacker that has a better aspect ratio, there is a bit more wind high up and I think that the high aspect main will be more effectiv too.

>>Wouter said:
-1- First is trivial, If both are sailing without a spi then the sloop is definately faster around the course.

>>Andreas said in my opinion :
If this would be the case, all the A-Cats would carry a gib....


The only reason why A-cats don't use a jib is because they have a overall sailarea limit in their rules. Meaning that any sailarea that goes into the jib must come out of the mainsail. If the A-cat rules did not limit this then we would only see A-cats with jibs. Add to this that A-cats like to race on courses where there is an upwind finish and you can see how the rules openly favour optimizing the boat for upwind sailing and take what ever bad you have on the downwind.

So the fact that A-cats don't use jibs ONLY says that for a given overall sailarea and the perfered race course a uni-rig is more efficient.

The truth of the statement above doesn't help us much when looking at courses that are not favoured to the upwind leg and when looking at designing a catamaran from scratch where any amount of sailarea is allowed to be put on a boat.

Again a sloop rig boat can ALWAYS have more sailarea than a uni-rig for a given righting moment or mastweight or acceptable pitching moment etc.

Due to the misunderstanding of the A-cats, and a few forcefull effort to propel the myth, quite a few sailors now believe that area put in the mainsail is AERODYNAMICALLY more efficient than the same amount put in the jib. This can simply not be maintained as a truth. If anything one most specify who one defines the measure of efficiency. I will give a few examples as colloberated by wind tunnel tests and measurements at sailboats. Spi are not included in the following points.

-1- The combination of a jib and mainsail produces MORE saildrive than just the mainsail. The interaction between the sails is the cause of this. The net effect is smallest on the upwind leg and increases (sometime strongly) when the apparent move increasing away from the bow. On all boats this means more speed. On downwind legs this means more depth

-2- The combination of a jib and mainsail produces MORE saildrive than just a mainsail of the same overall size on the same mast. The interaction between the sails is the cause of this. The net effect are smallest than in point -1-

-3- The combination of a jib and mainsail OFTEN produces MORE saildrive than just the mainsail of the same overall size on a taller mast. The interaction between the sails is the cause of this. In most cases it does in some case it does not. Pretty much in very light winds the taller rig produces more drive while in medium to heavy winds the shorter rig produces more drive.

-4- The speed of a sloop rigged boat (not talking VMG here) is always higher than the same platform with a uni-rig.

-5- VMG of a uni-rig boat MAY be higher on a upwind leg when the ratio's are carefully optimized. If they are not than the gains can well be zero or negative. The VMG on the downwind leg however is ALWAYS favouring the sloop rigged boat except in extreme light wind condition (laminair winds) Pretty much anything over 5 knots will favour sloops.

By fitting a spinnaker the uni-rigs correct out over their disadvantages downwind. However simply having a uni-rig upwind is not enough to beat sloops on the upwind. A great example of this was giving by two Tornado sailors last year (Medwell (Aus) of Tornado Alive). They had to sail without a jib against a training buddy or something with a jib. The sloop rig WON upwind. The sloop boat stayed powered up in the lulls and had slightly more boatspeed. The difference was small but it was definately there and when seconds count (as in the tornado class) then you want to sail with a jib.

What can we take away from this latter example. That the additional pointing of removing the jib in is NOT enough to compensate for the loss of speed. For the techies among us this means that the reduction of saildrive as a result of having less sailarea and despite the increase in mainsail drive due to reduced capsize/righting moment, was such that there was a significant speed loss. Pointing 5 degrees higher (at least) and still have inferiour VMG means you must loose at least 8 % speed (cos(40) / cos(45)). That is ALOT !

Increasing the mainsail area may OR may not help you. It will definately NOT help you in double trapeze conditions. I may marginally help you in medium conditions and without increases in mast height will NOT help you in light winds.

Adding area to the leach of a mainsail is NOT very effective when compared to adding it to a jib that can make use of the slot effect that is also so important in C-class boats. The way the slot works is also widely misunderstood but that is a different topic.

So what am I arguing here. That one can never say that a uni-rig is better then a sloop. Because that would suggest that it is alwasy better and that is certainly not the case. Can we say that they uni is worse than the sloop. No, by the same reasoning this is equally untrue.

Than can we look at the A-cats and conclude that uni-rigs are more often superior to a sloop than not ? No we can not as the answer is fully dependent on additional limits you state regarding the specifications of the design. The same reasoning holds visa versa.

Than what can be say about the comparison between the uni and sloop. First that sloop has gotten a rep that is doesn't deserve. We can say that uni-rigs are cheaper to produce. We can say that distance races tend to favour sloops because they are often held in conditions and on courses that is detrimental to the uni-rigs advantages. Uni-rigs perform by being succesful at working a balance act that underlies upwind VMG's while sloops rely more on brute force and brute speed to obtain VMG's.


Lets get on to point 2.

>>Wouter said:
-2- The unirig has the same overall sailarea as the main+jib combined of the sloop and both sailing with spis. With the right mast height (not too high) the uni will sail just as fast or slightly faster upwind than a sloop rig. While reaching the roles are reversed.

>>>Andreas said my opinion is :
When sailing under gennacker, the gib IMO dosn't do mutch.
I think the Uni will be faster, because with the higher mast, you can hoist a gennacker that has a better aspect ratio, there is a bit more wind high up and I think that the high aspect main will be more effectiv too.


The opinion of Andreas does not go against what I said. As I only talked about the upwind and the reachign leg (No spi). I agree that under spinnaker the jib is not doing very much. However I don't think the uni-rig is arguably faster. The hoist height and aspect ratio of the spi are afterall not directly linked to being a uni-rig or not. Afterall the HT's didn't have a higher aspect ratio than the F18's in the past. This was a diect result of the fact that the HT's had limited the hoist height to the same level as the F18's. With regard to heavy more wind up high. While this is theoretically true in practice the wind speed difference experienced at the top of a 9 mtr mast and 10 mtr mast is about 1 % in all winds above 5 knots. The Turbulant character of the winds makes the speed dependency to follow a parabolic curve and not a linear line as is the case at liminair winds. Combine this with the fact there is relative little sailarea this high makes the total net effect rather small. That is even before noting that the mainsail may only provide a 25 % of the total saildrive while sailing with a spi.

So if we run a imaginairy number example.

say 5 % more windspeed up high (far to much) => Lets round up upward by not looking at sailarea in the top so 5% more saildrive in the mainsail => power mainsail + power spi = 25% * 105 % + 75 % = 101.25 % more drive => taking 2.5 order root => 100.49 % more speed on downwind leg. Or 3 seconds on a long 10 minute downwind leg. This is less than the disadvantage you experience by sailing 5 kg overweight.

As you can see. gains in mainsail drive under spinnaker are quickly reduced in overall importance, Difference may end up being miniscule even though differences may really exist.

And this bring me to a second point. The fact that one can proof a certain difference must exist does not mean that its net effect is anything noticeable.

Sure a taller mainsail experiences slighly more wind high up there but this doesn't mean that it will make the boat differ on the downwind leg in any significant way.

In the end it is all about ratios and weigthing factors. Not about which one is theoretically more efficient Aerodynamically than another and which one can point higher. It is about which one strikes the best balance between conflicting phenomena. And sadly the last is rather sensitive to class rules and selfimposed limits.

This is why we see A-cats without jibs reach the A-mark first only to see them loose the race against F18's and have a fools chance of winning a distance race. And this is also why the F18 in turn has a serious weakspot to any 18 foot sloop rigged boat that weights in at 150 kg or less. And we can continue like that.

As a last point I would like to add that we really must pass the point of "I believe, I think, Could it be"; there is more than enough data available now to support all the points made above.

If anybody want to do some testing themselfs. Than I advice you to do the following :

Get another crew of equal skill, get two sloop rigged boat and race them against eachother while :

-1- Remove the spi from both boats and the jib of one sail a triangular course. Note the boat who wins most often.
-2- Remove the spi from both boats and the jib of one sail a windward leeward course. Note the boat who wins most often.
-3- Remove the spi from both boats and the jib of one sail a windward-leeward course with an upwind finish. Note the boat who wins most often.
-4- With spi but remove the jib of one boat and run the points 1 to 2 over again. Note the boat who wins most often.

I dare wager that the winner in all comparisons is one and the same boat although the margins of victory may be significantly reduced.

Which comparisons are left.

Jibless boat get larger mainsail and jibless boat get larger mainsail on larger mast.
This is a little more difficult if not expensive to test but we can already say that 4 out of 6 possible comparisons favour one particular setup over the other. There is only 2/6 = 1/3 of the comparisons left to favour the other one.

This should be enough to see that the situation is not as clear cut as the statement ;"If this would be the case, all the A-Cats would carry a gib.... "

That is all

Wouter

Hi Wouter

Allot of text ;-)

as you said:
-1- First is trivial, If both are sailing without a spi then the sloop is definately faster around the course.

i was thinking that you were talking of a restricted sail area, the same area for the uni and the sloop.

Now if we increase the sail area for a sloop, to the max a plattform can carry for a given windspeed, i agree that the sloop (with the same sail area) will be faster and the uni is in trouble, but as soon that there is less wind, this advantage will be lost to the uni and the uni is faster.

greetings from cold switzerland!

Plus uni's are cooler looking....

Nice looking boat Andreas! Do you prefer sitting cross leg facing forward while driving downwind? Are you doing that so you dont get in the way of your crew? How do you keep from sliding down the tramp? Dont you find it more comfortable to sit on the hull?

Bill

Hi Bill

Do you prefer sitting cross leg facing forward while driving downwind?

no not actually ;-)
In this picture we were just sailing towards the spectators boat (thats were the picture was made from) and had allot of boats around us. so i guess the reason for the unusual position was to have a better view at the other boats around us.
Normally I sit on the hull, in rough conditions one leg goes to the daggerboard, to prevent forward motion and i hold my self with my outer hand on the beam.

You seem to be overlooking one small fact Wouter when comparing uni with sloop (same boats) and that is that most (not all of course) cats when sailing sloop rigged sail with two people on board but usually only with one person on board when uni, this weight difference obviously will have a strong bearing on the comparitive performances.
The most obvious example of this in Australia where the uni/sloop contest has been in hot competition for over 30 years between the sloop and the cat rigged mosquitoes. The results have varied over the years when for some time the uni's have been superiour and for other years the sloop have had the ascendency. About the only real conclusion that could be drawn over such a long period of time is that the only real difference has been the quality of the sailing skills of the people in the relative classes at the time and that in either form the boats were too close in performance to be able to make any truely OBJECTIVE conclusion.

I didn't overlook that. I just find it self evident that the comparisons are made between boats that are the same in every respect except in the differences that were stated. There is never any point in comparing apples with oranges.

All I said holds true when comparing doublehanders with eachother or singlehanders with eachother. As long as you don't compare doublehanders with singlehanders and visa versa.

Wouter