Cats Sailing to Wind

[Factor]

Originally Posted by Palarran

Would you mind explaining it to me? The part about inducing leeway. I'm pretty sure I understand apparent wind and VMG but maybe not the concept of making your boat have worse leeway to increase VMG.

See what Monte said above, its achievable with all boats but easier (more rewarding) to do with a dagger board cat. All boats suffer leeway including monos and multis, some more than others,

So using random figures and numbers. Imagine you next waypoint is 5nm away. Your rhumb line has you with the wind at 110 degrees off the bow and the apparent wind at that stage is say 10 knots. if you bring the apparent up to say 80 degrees by pointing higher into the wind, you will increase apparent wind speed and boat speed, but you will be off your mark, if however you raise the boards on a daggerboard boat you will start to suffer more leeway, except in this case its no suffering as your CMG (Course Made Good will have you off you actual heading because of the leeway, so you sail at say 8 knots instead of 5, and your distance covered is the same. so you can gain quite a massive advantage by doing this.

In a minikeel boat you can't get rid off the keels but you can induce leeway by moving the centre of effort forward by adjusting trim. Also the slower the boat speed the more effect that leeway will have, so this idea works better for mini keel boats when you have lower boat speeds.

Leeway is usually not desirable, but when like all things in sailing sometimes you can make it work for you. The benefit of daggerboards is you more easily choose greater or lesser leeway.

[Palarran]

Originally Posted by monte

When sailing off the wind, sliding sideways to the wp will allow you to point higher, increasing apparent wind. I.e, inducing 10 degrees leeway by raising boards can allow you to point 10 degrees higher which will likely be faster on most points of sail from a broad reach to beam reach.

Originally Posted by Oliver L.

Hi, Monte,

I disagree fundamentally about the ability to sail better by "sliding sideways". You increase the drag of the hulls and you don't gain anything in the wind direction, except that you are turning your forestay a bit to windward, which might give you a tiny bit of additional exposed genoa.

Specifically the leeward airstream, which we multihullers so love and which makes us gybe downwind, won't happen because you are just turning the boat slightly while maintaining course.

...not that I have tried it, my boat comes with fixed keels...

Oliver

Thanks Monte. I must be slow on the learning or like Oliver simply haven't been able to experience it due to fixed keels. I get the concept of having a wider wind angle to gain speed and VMG. I just don't see how increasing leeway is helpful. Have you seen any illustrations? Starting Google search myself now.

[Palarran]

Originally Posted by Factor

See what Monte said above, its achievable with all boats but easier (more rewarding) to do with a dagger board cat. All boats suffer leeway including monos and multis, some more than others,

So using random figures and numbers. Imagine you next waypoint is 5nm away. Your rhumb line has you with the wind at 110 degrees off the bow and the apparent wind at that stage is say 10 knots. if you bring the apparent up to say 80 degrees by pointing higher into the wind, you will increase apparent wind speed and boat speed, but you will be off your mark, if however you raise the boards on a daggerboard boat you will start to suffer more leeway, except in this case its no suffering as your CMG (Course Made Good will have you off you actual heading because of the leeway, so you sail at say 8 knots instead of 5, and your distance covered is the same. so you can gain quite a massive advantage by doing this.

In a minikeel boat you can't get rid off the keels but you can induce leeway by moving the centre of effort forward by adjusting trim. Also the slower the boat speed the more effect that leeway will have, so this idea works better for mini keel boats when you have lower boat speeds.

Leeway is usually not desirable, but when like all things in sailing sometimes you can make it work for you. The benefit of daggerboards is you more easily choose greater or lesser leeway.

Ok, I can maybe see your point but I thought we were talking about sailing into the wind. IE, the rhumb line and true wind are the same.

[Factor]

Originally Posted by Palarran

Ok, I can maybe see your point but I thought we were talking about sailing into the wind. IE, the rhumb line and true wind are the same.

Noted. Always remember though even when the waypoint is directly on the nose it doesn't matter how fast or high you sail, what matters is how long it takes you to get there, most times the shortest distance is not the shortest time.

[Palarran]

Originally Posted by Factor

Noted. Always remember though even when the waypoint is directly on the nose it doesn't matter how fast or high you sail, what matters is how long it takes you to get there, most times the shortest distance is not the shortest time.

That I completely understand

[2Wind]

Thanks Monte and Factor for this explanation. Whilst I didn't appreciate this in theory, I suspect I've been doing it unwittingly when chasing VMG.

As I couldn't sail today because of foul weather, I've had some time to review the track data on my recent trip to Lord Howe. For the purposes of the discussion, please look only at the outbound track as marked.

Presentation1.pdf

Firstly, the wind remained fixed at SE throughout the voyage and for that matter for a further 5 days thereafter.
The rum line was at a bearing of 130 degrees, almost directly to windward.
The AP was set most of the time to Wind Vane mode steering an AWA of 35 to maintain VMG and avoid periodic stalling of the genoa as can happen when trying to sail higher (30 degrees) with the AP in lazy response mode (battery saving). Thus the boat maintained an apparent course of 100 degrees throughout most of the voyage east, other than for a few southward tacks to be mentioned below. Yet the CMG was clearly parabolic.

The actual track was in three parts.

Highlighted section 1. shows a track well to the south due to the East Australian Current running at about 3.5 kts from north to south, flattering the course made good by a significant margin. What a ride!

Highlighted section 2. marks a period tracking to the east and in the middle of the circled area some slight northering.

Presentation2.pdf

This is a zoomed view of this transition. We became aware that our track had swung significantly. Thinking we had a wind shift we tacked south, only to note that our SOG dropped to 4.5 kts while our boat speed remained at 7.5 to 8.0kts. It took a little time for the penny to drop with recognition that we had entered the reciprocal south to north current that usually lies significantly further east. One can see how adverse was the effect of both the slowing in SOG and a change in sea-state as associated with the current, on the tack angles which were near 110 degrees.

Finally we sailed out of the current, and then settled into what I might have thought was the predicted track given the wind angle. Once at Middleton Reef, we tacked south, clear of adverse current, making a 90 degree tack angle, despite a ongoing significant sea-state (2-3m seas).

Now back to you usual program.....

[Factor]

Originally Posted by 2Wind

The rum line was at a bearing of 130 degrees, almost directly to windward....

I am reminded of the adage regarding sailing to Lord Howe from Brisbane, sail south until you think you will get a fair run to to Lord Howe, then sail south another day or two.

It is such a beautiful destination though, its worth the effort to get there.

[donradcliffe]

Those tacks in the counter current were pretty ugly, emphazing factor's adage that you needed to get south in the EAC before you head offshore to Lord Howe.

OTOH, I can't agree with factor's "sliding sideways makes you go faster', because the leeway will decrease your apparent wind.






eac

[arsenelupiga]

Originally Posted by Factor

It is such a beautiful destination though, its worth the effort to get there.

centre of earth.

On my list to do next.

[Polux]

Originally Posted by 44'cruisingcat

Your boat was longer.... Jeanneau's aren't good windward mono's..... the guy must have been a terrible sailor, whereas you are a genius..... you must have had current with you.... I'm sure Pollux will fill in the excuses.. er details.

No, you pretty much say it all

I have said repetitively that you can compare the performance on a short sailing like the one on the Barramundi but in what regards a passage of many days, like the one in question, it is no use to compare two single boat's performance since on that case the way the boat is sailed, particularly at night, can be more important than the boat itself.

I remember a guy with a Bavaria 36 that circumnavigated solo saying that while crossing the Pacific he out performed several cats. That does not mean that a Bavaria 36 sails faster than bigger cats but that he sails faster then the sailors on those cats.

That's why I think that you can only get relevant results were you have many boats of the two types involved, like on the ARC, that allows you to have some average results and also boats of both types well sailed, meaning close to his best performance.

You can also have meaningful results in races where production boats of both types race, like the Fastnet. On other hand, race results of one offs or very small cruising racers more pointed to racing than long range cruising, don't give reliable results, except in what regards those particular boats that are not the cruising boats one can have (not production) or too small and race oriented for serious cruising.

I was really not replying to that, but as you insist I cannot let you be disappointed

[Polux]

Originally Posted by 44'cruisingcat

LOL! No no! He's totally unbiased! He'll tell you that constantly, while he's here in the multihull forum, endlessly sniping at multihulls.

I have said it and I say it again. I don't think multihulls need a forum or any special protection for that matter. I like sailboats, all type of sailboats and I post in all forums.

You, like many on that segregated sail forum, act in a very defensive position and comments like that one about my girlfriend being stolen by a multi hull sailor (posted by another poster) is relevant only to his bad manners and inconvenience. For the record I am happily married for more than 30 years and I don't have girlfriends.

As I have said repetitively I like multihulls and could easily have one instead of a mono:In what I am concerned, it is all about what money can offer to you in what regards sailing and personal tastes and I am not the only one that thinks that way.

Unfortunately there are many that see is choice of a boat like the only right one and that in a kind of fundamentalist way defend it as the only right one and this is valid not only to monohulls versus multihulls but also versus performance boats versus slower but more spacious boats, that some call condo boats.

All boats are compromises, all have advantages and disadvantages and all are suited for some type of sailors and performance is certainly not the thing most put ahead when buying a cruising sailboat.

[Polux]

Originally Posted by 2Wind

I think it's true that if I really want to go fast and tight to windward, I'd need a Maxi, but not just any Maxi. I'm thinking Wild Oats IX (narrow beam, several foils, hydraulic canting keel, aerodynamic mast, and a crew of 12). I'd have Comanche on hold for the fast down wind legs, or perhaps a Volvo 70.
....
Anyway, can we at least agree, that cats perform better to windward than square riggers, and house boats. Then I'll be happy and will remain quietly content with my boat's (small 'p") performance.
.

Yes certainly we can, not only better than square riggers but better all sailboats from the XIX century, except if they were very special race boat's, type of America's cup race boats of that time.

The truth is that the sailing ability of monohulls is far from being the same. Sure an optimized upwind racer like Wild Oats can go incredibly into the wind but many other small racing boats can do as well and many performance cruisers, without doing as well can have a remarkably good performance.

Among cruising monohulls the performance upwind can be very different. I would say most modern ones with decent conditions will do 45º degrees real tacking angle, performance ones will do better than that but boats with a center board, swallow draft keels or full keels will not probably be able to do a 45º tacking angle and will have more leeway (as well as all boat that offer a lot of windage).

Anyway regarding the point the OP was interested in, there is no doubt that modern cats with keels can not only go to windward but go well to windward.

Off course if most of the sailing is done to windward or if one has special pleasure to sail to windward, that would not be the ideal type of boat to have, but that is not the case with the OP and not the case with the vast majority of cruisers.

[44'cruisingcat]

Originally Posted by Polux

Yes certainly we can, not only better than square riggers but better all sailboats from the XIX century, except if they were very special race boat's, type of America's cup race boats of that time.

The most positive thing I've seen you say about multihulls! Well done! Some cat's might sail to windward better than some mono's from 200 years ago! (But not all of them of course).

Yeah, I can see you're a real fan....

speaking of America's cup boats, did you see how the AC72's sailed to windward?

VMGs better than 18 knots in no more than 20 knots breeze...

I know you're a big fan of polars, can you post a polar of a mono that does better?

[Barra]

Originally Posted by donradcliffe

Those tacks in the counter current were pretty ugly, emphazing factor's adage that you needed to get south in the EAC before you head offshore to Lord Howe.

OTOH, I can't agree with factor's "sliding sideways makes you go faster', because the leeway will decrease your apparent wind.






eac

Yes the induced leeway will reduce the AWS slightly but overall increase in boat speed and therefore NET AWS increase from hitting your boats sweet spot wind angle is far greater

Add to that less underwater drag from only the rudders and SDs giving better boats speed from a given wind speed and its a clear and significant increase in VMG.

In really light winds say under 5 knots ive found the loss of AWS from the leeway like you summise more noticable so its probably a greater proportion on the overall AWS effect but even then the need to point lower in light air means theres no noticable VMG gain.

You can play similar tricks with wind against tide situations where raised boards can generate enough leeway to offset opposing currents and sail a better wind angle.

The point is boards give FLEXIBILITY to trim the boat better to conditions so in nearly all wind angles you will be faster.

[Palarran]

Originally Posted by Barra

Yes the induced leeway will reduce the AWS slightly but overall increase in boat speed and therefore NET AWS increase from hitting your boats sweet spot wind angle is far greater

Add to that less underwater drag from only the rudders and SDs giving better boats speed from a given wind speed and its a clear and significant increase in VMG.

In really light winds say under 5 knots ive found the loss of AWS from the leeway like you summise more noticable so its probably a greater proportion on the overall AWS effect but even then the need to point lower in light air means theres no noticable VMG gain.

You can play similar tricks with wind against tide situations where raised boards can generate enough leeway to offset opposing currents and sail a better wind angle.

The point is boards give FLEXIBILITY to trim the boat better to conditions so in nearly all wind angles you will be faster.

What confused me is that this thread was discussing sailing upwind and then reaching or broad reaching tactics came into the discussion with little transition. All of us have different tricks for better boat speed at wider angles, the real tough part is upwind. That's really where your boat should excel past fixed keel boats.