Catamaran tacking angles , really that bad???

[fxykty]

Originally Posted by arsenelupiga

we are discussing rough seas here, not flat water. You will not do 8 kn in 20 kn of wind here unless on suicide mission. if you ever have sailed cat in rough upwind enough, you will notice that waves are telling you how fast and what angle you can go. Boat type has little to do with it. if you try too hard boat will be launched in next wave and larger forces than you want will play with your rig. In these conditions boat robustness build is the key. Sure, boat with smaller bridgedeck will do bit better.



ok, now i am ready to listen to your fairytale how performance cats posses magic in such conditions , please . Ever i watched one, never seen that magic, heheh.



please bring in CC44. sure he will add extra story or 2 with video behind island flat water upwind sail

You are talking from your experience on a Lagoon 400, right? Maybe 8 knots is suicidally fast on your boat? Not on ours. Those are two separate data points. Lots of others can add their own.

Of course wind and seas determine the speed you want to go, but until you get to storm conditions they don’t determine the wind angles you can sail. On our boat and others like it. Sailing Zatara’s latest video showed them motoring into 15-20 knots of wind and it looked awful - surely sailing would have been more comfortable even with their boat? YMMV

We sail lots around the Hauraki Gulf, just off Auckland. Depths average 30-40m and fetch on the long axis up to 50 miles and down to 20 miles on the short. Wind waves to 2-3m on a pretty short shallow water period (similar to Baltic Sea perhaps?).

Since we are weekend and holiday sailors around town, we cannot always pick our weather and spend at least half the time close hauled.

20 knots will be breaking 2m waves on a short wavelength, less than 5 seconds and 10-15m on the water. With 25 knots over the deck we’ll have one reef in the main and a full jib, wind angle at 34 degrees apparent and boat speed 8.5 knots, 5-7 degrees of leeway. Less leeway, tighter apparent wind angle, and 9 knots boat speed in flatter water (gotta love an offshore breeze).

Offshore, probably 4-5m swell with occasional breaking tops, wind waves up to 1m on top of the swell. Our boat performs as in flat water. Though offshore in those conditions we may have a second reef and speed 8-8.5 knots.

Our cat has a small heel, with lots of pressure on the leeward hull, depressing it 5cm or so. Waves hit the windward bow first, start to lift it but then raise the lee bow and the windward bow dips. Next wave sprays over the windward bow and lifts it back level, lee bow cuts through that wave and we’re back to the beginning.

Occasional launches off bigger waves, but we’ve got reasonably long hulls, so the impacts are not that bad. We do use running backstays to keep the mast more steady and run our rigging tight enough so that the leeward shroud does not move around.

Offshore in larger swells and shorter wave period, say a quick building low or over a seamount, we’ll slow down to prevent excessive slamming. Typically it takes 40 knot seas to make us slow down to stay more comfortable. By then we’re on our third reef and staysail, maybe even storm jib. No need to change the angle if we need a close-hauled course.

We have a 55 foot Gunboat near our berth and they report having to slow down to below 20 knots in rough seas. But they also run a full professional crew.

[Joli]

The only number that matters upwind is vmg.

[Sailor 99]

Originally Posted by Moontide

One thing that is not talked about much is that older heavy displacement monohull cruisers don't do much better, if at all. Newer lighter monohulls do have better numbers.


.

Have an 86 Idylle 51. New sails. Big rig. 1550 sq ft of sail that she can carry into 20 knots up wind at 30 degrees AWA. She goes well but once you get into heavy waves performance dives due to leeway and the speed of the water headed down wind.

You get on something like a Bayfield 36 or the and you will be losing ground in 25 knots of wind and accompanying waves.

Nobody considers the speed of the water going down wind. It is huge.

A wave travels at a speed equal to 1.34 X the square root of the wave period (in ft) for instance say a wave is 144 ft crest to crest. Then take 12 x 1.34 =16.08 knts.

[fxykty]

Originally Posted by Dark Horse

Have an 86 Idylle 51. New sails. Big rig. 1550 sq ft of sail that she can carry into 20 knots up wind at 30 degrees AWA. She goes well but once you get into heavy waves performance dives due to leeway and the speed of the water headed down wind.

You get on something like a Bayfield 36 or the and you will be losing ground in 25 knots of wind and accompanying waves.

Nobody considers the speed of the water going down wind. It is huge.

A wave travels at a speed equal to 1.34 X the square root of the wave period (in ft) for instance say a wave is 144 ft crest to crest. Then take 12 x 1.34 =16.08 knts.

But you know that the water in a wave doesn’t travel, right? It’s the pressure that moves, not the water. Yes, at the crest water moves in the wave direction, especially if breaking, but that water then moves backward in the trough.

You seem to be referring to current - that’s completely separate to the water movement due to waves.

[arsenelupiga]

Originally Posted by fxykty

You are talking from your experience on a Lagoon 400, right? Maybe 8 knots is suicidally fast on your boat? Not on ours. Those are two separate data points. Lots of others can add their own.

Of course wind and seas determine the speed you want to go, but until you get to storm conditions they don’t determine the wind angles you can sail. On our boat and others like it. Sailing Zatara’s latest video showed them motoring into 15-20 knots of wind and it looked awful - surely sailing would have been more comfortable even with their boat? YMMV

We sail lots around the Hauraki Gulf, just off Auckland. Depths average 30-40m and fetch on the long axis up to 50 miles and down to 20 miles on the short. Wind waves to 2-3m on a pretty short shallow water period (similar to Baltic Sea perhaps?).

Since we are weekend and holiday sailors around town, we cannot always pick our weather and spend at least half the time close hauled.

20 knots will be breaking 2m waves on a short wavelength, less than 5 seconds and 10-15m on the water. With 25 knots over the deck we’ll have one reef in the main and a full jib, wind angle at 34 degrees apparent and boat speed 8.5 knots, 5-7 degrees of leeway. Less leeway, tighter apparent wind angle, and 9 knots boat speed in flatter water (gotta love an offshore breeze).

Offshore, probably 4-5m swell with occasional breaking tops, wind waves up to 1m on top of the swell. Our boat performs as in flat water. Though offshore in those conditions we may have a second reef and speed 8-8.5 knots.

Our cat has a small heel, with lots of pressure on the leeward hull, depressing it 5cm or so. Waves hit the windward bow first, start to lift it but then raise the lee bow and the windward bow dips. Next wave sprays over the windward bow and lifts it back level, lee bow cuts through that wave and we’re back to the beginning.

Occasional launches off bigger waves, but we’ve got reasonably long hulls, so the impacts are not that bad. We do use running backstays to keep the mast more steady and run our rigging tight enough so that the leeward shroud does not move around.

Offshore in larger swells and shorter wave period, say a quick building low or over a seamount, we’ll slow down to prevent excessive slamming. Typically it takes 40 knot seas to make us slow down to stay more comfortable. By then we’re on our third reef and staysail, maybe even storm jib. No need to change the angle if we need a close-hauled course.

We have a 55 foot Gunboat near our berth and they report having to slow down to below 20 knots in rough seas. But they also run a full professional crew.

ok, nice story. I watched vagabonde on utube going upwind and hey, that was a mess. 3-4 kn VMG calculated by plotter, so real VMG was less.

i have sailed a bit upwind in all sorts of stuff and observed so called performance cats and is nothing what you say. Differences between ours and these cats in open seas are less than what one would hope, after reading CF. Some do push faster but then repair bill is nontrivial.

[wingssail]

Originally Posted by arsenelupiga

...going upwind and hey, that was a mess. 3-4 kn VMG calculated by plotter, so real VMG was less...

Why do you think real VMG was less than stated on the plotter?

[Sailor 99]

Originally Posted by fxykty

But you know that the water in a wave doesn’t travel, right? It’s the pressure that moves, not the water. Yes, at the crest water moves in the wave direction, especially if breaking, but that water then moves backward in the trough.

You seem to be referring to current - that’s completely separate to the water movement due to waves.

Of course the water moves and it is easily shown. It is called seiche and storm surge.

The images are Lake Erie snap shot right now at time of posting. 2 meters one at each end of the lake.

It has been blowing out of the East North East for 2 days. The lake has risen 25 inches in the west.


This is meter at Toledo Ohio

https://tidesandcurrents.noaa.gov/st...d=9063085#info



This is the meter at Buffalo NY.

https://tidesandcurrents.noaa.gov/st...tml?id=9063020

The water has dropped by roughly the same amount

This will level out when the wind stops blowing or it will reverse when the wind starts to blow west.

That is about 100 billion us gallons of water that moved from one end of the lake to the other.

This happens on every large lake. But if the lake is deep it is not this dramatic as the water can move along the bottom to fill back in the low side the water is blown out of. Lake Erie is shallow.

Same thing happens on the ocean.

[wingssail]

Originally Posted by Dark Horse

Of course the water moves and it is easily shown. It is called seiche and storm surge.

The images are Lake Erie snap shot right now at time of posting. 2 meters one at each end of the lake.

It has been blowing out of the East North East for 2 days. The lake has risen 25 inches in the west.


This is meter at Toledo Ohio

https://tidesandcurrents.noaa.gov/st...d=9063085#info



This is the meter at Buffalo NY.

https://tidesandcurrents.noaa.gov/st...tml?id=9063020

The water has dropped by roughly the same amount

This will level out when the wind stops blowing or it will reverse when the wind starts to blow west.

That is about 100 billion us gallons of water that moved from one end of the lake to the other.

This happens on every large lake. But if the lake is deep it is not this dramatic as the water can move along the bottom to fill back in the low side the water is blown out of. Lake Erie is shallow.

Same thing happens on the ocean.

No, No, No!

Yes there is a push towards the leeward side of the lake (or ocean).

But it is nowhere equivalent to the speed of the waves.

If you are sailing into waves the actual motion of the water to leeward is insignificant compared to the motion imposed by the force of the wave against your bow. That is offset by the motion of the wave behind you pushing you foreword.

So you get slapped by the wave coming in but you're supported by the wave's trough as it passes.

Those two forces are not equal so you get pushed to leeward unless you have a boat whose hull shape and sail power allow it to move forward against those wave forces.

[Sailor 99]

Originally Posted by wingssail

No, No, No!

Yes there is a push towards the leeward side of the lake (or ocean).

But it is nowhere equivalent to the speed of the waves.

A billion gallons of water moved west in 12 hours ( up hill most of the time) and it makes no difference?

You can argue about the details all you want but to say it does not make a difference? Sorry. Provably false.

But you can sail your boat and I will sail mine. You plan your course, I will plan mine.

[Jim Cate]

Originally Posted by Dark Horse

You can argue about the details all you want but to say it does not make a difference? Sorry. Provably false


But you can sail your boat and I will sail mine. You plan your course, I will plan mine.

Y ou might want to do a little reading before you spout off like this, DH.
Here's a link to a simple discourse upon the subject:

https://ci.coastal.edu/~sgilman/770Oceansinmotion.htm

But I can sum it up if you don't want to do this... you are wrong and Wingsail is right.

Jim

[Factor]

Originally Posted by arsenelupiga

ok, nice story. I watched vagabonde on utube going upwind and hey, that was a mess. 3-4 kn VMG calculated by plotter, so real VMG was less.

i have sailed a bit upwind in all sorts of stuff and observed so called performance cats and is nothing what you say. Differences between ours and these cats in open seas are less than what one would hope, after reading CF. Some do push faster but then repair bill is nontrivial.

One of the boats (Cats) I crew on can tack in under 90 degrees and one of the tris will not be between to windward by anything, and I mean anything. There is a lagoon 39 in our mid week fleet that simply cannot make VMG to windward.

[Factor]

Originally Posted by SaltyBlonde

I looked into this a bit when shopping for my Cat and what I kept getting told was that once you get over 40' on a Cat, going upwind is pretty much a motor endeavor. I opted for my lil 30' because it has daggerboards and the combo of the daggerboards and shorter length, seem to avoid those notorious upwind Cat problems. I've got afew kinks to work out on my lil fixer upper before I take her out, so I have yet to prove this theory, but it came up often enough with reputable folks that I felt there must be some truth to it.

I dont know who told you that, but they have no idea. Many Schionnings and Outremers and even seawinds can happily sail at speed upwind. I have a million bucks that says I can sail upwind on a 50 foot cat, not all of them and certainly on few that have minikeels but many many of them.I mean real ones built for sailing not for the charter market

[double u]

Originally Posted by Jim Cate

Y ou might want to do a little reading before you spout off like this, DH.
Here's a link to a simple discourse upon the subject:

https://ci.coastal.edu/~sgilman/770Oceansinmotion.htm

But I can sum it up if you don't want to do this... you are wrong and Wingsail is right.

Jim

of course right, Jim. There is going to be some "surface drift" though, at times not inconsiderable (a full knot on our 2019 crossing to the Marquesas)
https://spaceplace.nasa.gov/la-nina/en/ : "In normal conditions, winds above the Pacific Ocean gently push warm water west."
"Warm water moves west during a La Niña"

[Sailor 99]

Originally Posted by Jim Cate

Y ou might want to do a little reading before you spout off like this, DH.
Here's a link to a simple discourse upon the subject:

https://ci.coastal.edu/~sgilman/770Oceansinmotion.htm

But I can sum it up if you don't want to do this... you are wrong and Wingsail is right.

Jim

Spouted off? Seems rather rude, especially coming from a moderator. I am disappointed.


And then you are wrong to boot. It's basic physics.

Here is some reading for you.

https://en.wikipedia.org/wiki/Wind_generated_current

https://www.sciencedirect.com/topics...driven-current

https://phys.org/news/2020-09-major-...-shifting.html

https://www.britannica.com/science/w...en-circulation

https://oceanexplorer.noaa.gov/facts/currents.html

https://journals.ametsoc.org/jpo/art...opical-Pacific

100 billion gallons of water does not move 200 miles west in 12 hr and not create some kind of a current.

That you don't believe in it does not make it any less of a fact. To say that it does not make a difference to a boat going to wind in 20-25 knots with big wave that is making perhaps 6-7 knots up wind ( fast mono) which is about 4-4.5 knots vmg at best while being punched back by waves and leeway is disingenuous

We can argue about what the current rate is but that it exists is undeniable.

Perhaps you should moderate your own post.

[chrisr]

Originally Posted by Dark Horse

Spouted off? Seems rather rude, especially coming from a moderator. I am disappointed.


And then you are wrong to boot. It's basic physics.

Here is some reading for you.

https://en.wikipedia.org/wiki/Wind_generated_current

https://www.sciencedirect.com/topics...driven-current

https://phys.org/news/2020-09-major-...-shifting.html

https://www.britannica.com/science/w...en-circulation

https://oceanexplorer.noaa.gov/facts/currents.html

https://journals.ametsoc.org/jpo/art...opical-Pacific

100 billion gallons of water does not move 200 miles west in 12 hr and not create some kind of a current.

That you don't believe in it does not make it any less of a fact. To say that it does not make a difference to a boat going to wind in 20-25 knots with big wave that is making perhaps 6-7 knots up wind ( fast mono) which is about 4-4.5 knots vmg at best while being punched back by waves and leeway is disingenuous

We can argue about what the current rate is but that it exists is undeniable.

Perhaps you should moderate your own post.

i think if everyone steps back a bit and thinks you will realise you are both right and actually talking about different things

in surface drift & current the actual water molecules move...sometimes at significant speed

on the other hand in a WAVE the molecules do not move...the energy does

these are two different phenomena

now please kiss & make up

cheers,