Catamaran tacking angles , really that bad???

[catsketcher]

Tacking angle is a function of lift from the rig and drag of the hull and rig. Fast and close-winded boats have nice rigs that develop lift at low angles of attack - nice flat sails and tight forestays produce low drag at shallow angles of attack. They may not be high lift (thrust) but that is okay because the boats don't need heaps of power, they slip through the water sweetly with their low decks, no large cabins, and carefully sanded light, thin hulls.

As soon as you increase drag in any way, with more weight, fatter hulls, more air resistance you have to increase energy from the rig. The only way we can do this is to increase the angle of attack of the sails. Make the sails fuller (to make more power from the rig) and you have to bear away. It really is basic physics.

Go out sailing on a small dinghy and then throw a bucket over the back. As soon as the bucket's line starts dragging the boat, you have to bear away or the boat almost stops and the daggerboard stalls. Same with if you are too far aft and the transom sinks. Bearing away upwind occurs because the boat is harder to push through the water. You can't get away from the physics.

So any boat with a flybridge, heavy displacement, fat hulls, non folding props, immersed sterns, flat front windows, etc is going to sail lower than those that do not have these attributes. Racing boats win races on height, so look at how they are designed. That is how you design a boat to go upwind well.

As has been said, VMG is not always highest at less than 100 degrees. The GP 50 cats show this. But for most people sailing at around 7-9 knots upwind in 12-25 knots you will probably find a nice cruising cat can do around 100 degrees between tacks on the chart (including leeway).

Only you can work out whether you can handle the upwind performance of a condocat. Personally, I would rather not sail than take a badly performing boat upwind. I find sailing upwind on a nice cat so pleasurable that to sail one that couldn't chomp along at 8 knots all day at 50 degrees angle made good would drive me crazy. As 44C shows, you can have a great and roomy boat that goes to windward really well with a big interior.

You really can feel the drag when going upwind. The boat surges sideways and you are always on the helm, bearing away after each wave to get the thing going again. But on a nice sailing boat, well designed, the boat slips along and you can dig upwind with the wheel, to bite into a higher angle because she sails so nicely. She wants to work with the wind and edge up, instead of wanting to sag. She doesn't slow quickly if you go a little high. Go sailing on a nice cat that needs a bottom job and then scrape the barnacles off. The effect of decreased drag totally transforms the pleasure of sailing for me.

cheers

Phil

[Seaslug Caravan]

Originally Posted by stevensuf

I


Are they really that bad???


?

Can be.

Depends on the sea state and what the level of discomfort the crew are prepared to put up with.

As soon as one starts to throttle back in a seaway the boats windage wins out and the whole shaboodle starts sliding to leeward.

Falling out the back of swells at 10 knots has got knobs on it.

[barnakiel]

C'mon guys bring on more of those vids with floppy shrouds and baggy sails! They are fun!


I also like all the judgements based on vids in flat water. Because anything will go upwind in flat water!



I cannot comment on 440 but the newer 450 sails reasonably well upwind (and downwind) - above and beyond Formosas and other typical cruising hardware. Yet they are less close winded than a very modern sporty cruising mono (by about 10 degs maybe).



Two of my clients have L450 boats. They have some quality problems but zero sailing performance problems.



A separate factor is their speed. You sail wider, you sail faster, you may reach that upwind mark before same sized mono does.




Cheers,
b.

[admiralslater]

Originally Posted by barnakiel

C'mon guys bring on more of those vids with floppy shrouds and baggy sails! They are fun!


I also like all the judgements based on vids in flat water. Because anything will go upwind in flat water!



I cannot comment on 440 but the newer 450 sails reasonably well upwind (and downwind) - above and beyond Formosas and other typical cruising hardware. Yet they are less close winded than a very modern sporty cruising mono (by about 10 degs maybe).



Two of my clients have L450 boats. They have some quality problems but zero sailing performance problems.



A separate factor is their speed. You sail wider, you sail faster, you may reach that upwind mark before same sized mono does.




Cheers,
b.

I agree it is critical that the the boats compared ( cats and monohulls) are designed with a similar end goal .
Ie full cruiser, or cruiser racers . IMO boats like the Outremers and katanas are cruier racers and they should be the benchmark for boats like the square chined Beniteau modelled after the volvo sleds

[stevensuf]

Originally Posted by admiralslater

I own a 2003 Outremer 45 and the same vintage Pdq 36 that was custom fitted with boards . My #are very good on these to boats so not much use to you as the op. I did want to relate to you a conversation I had with the the owner of an Amel 40 something who is going around the world. I had never been on one so as I visited I asked about performance etc . Her reply to the upwind question was the boat was so poor in that direction that she would not really consider it .
I say this. Not comment about the Amel or any other boat but to make sure that comparisons are done on boats that share the same design criteria .There are lots of crusing monohulls that aren't great up wind and lots of Multhulls that aren't either .
You just have to pick what you can live with

I me ta delivery skipper in the azores with an amel 55, he said it would not go to the wind. Lovely boat mind you!

[Hardhead]

Originally Posted by catsketcher

Tacking angle is a function of lift from the rig and drag of the hull and rig. Fast and close-winded boats have nice rigs that develop lift at low angles of attack - nice flat sails and tight forestays produce low drag at shallow angles of attack. They may not be high lift (thrust) but that is okay because the boats don't need heaps of power, they slip through the water sweetly with their low decks, no large cabins, and carefully sanded light, thin hulls.

As soon as you increase drag in any way, with more weight, fatter hulls, more air resistance you have to increase energy from the rig. The only way we can do this is to increase the angle of attack of the sails. Make the sails fuller (to make more power from the rig) and you have to bear away. It really is basic physics.

Go out sailing on a small dinghy and then throw a bucket over the back. As soon as the bucket's line starts dragging the boat, you have to bear away or the boat almost stops and the daggerboard stalls. Same with if you are too far aft and the transom sinks. Bearing away upwind occurs because the boat is harder to push through the water. You can't get away from the physics.

So any boat with a flybridge, heavy displacement, fat hulls, non folding props, immersed sterns, flat front windows, etc is going to sail lower than those that do not have these attributes. Racing boats win races on height, so look at how they are designed. That is how you design a boat to go upwind well.

As has been said, VMG is not always highest at less than 100 degrees. The GP 50 cats show this. But for most people sailing at around 7-9 knots upwind in 12-25 knots you will probably find a nice cruising cat can do around 100 degrees between tacks on the chart (including leeway).

Only you can work out whether you can handle the upwind performance of a condocat. Personally, I would rather not sail than take a badly performing boat upwind. I find sailing upwind on a nice cat so pleasurable that to sail one that couldn't chomp along at 8 knots all day at 50 degrees angle made good would drive me crazy. As 44C shows, you can have a great and roomy boat that goes to windward really well with a big interior.

You really can feel the drag when going upwind. The boat surges sideways and you are always on the helm, bearing away after each wave to get the thing going again. But on a nice sailing boat, well designed, the boat slips along and you can dig upwind with the wheel, to bite into a higher angle because she sails so nicely. She wants to work with the wind and edge up, instead of wanting to sag. She doesn't slow quickly if you go a little high. Go sailing on a nice cat that needs a bottom job and then scrape the barnacles off. The effect of decreased drag totally transforms the pleasure of sailing for me.

cheers

Phil

Phil - this is one of the best posts I've read on this subject. Thanks for taking the time to post it-

[44'cruisingcat]

Originally Posted by admiralslater

That looks like a really nice boat and a great day for sailing . I have never seen telltales on the back side of the cabin though.

That's our high tech rainwater collection system. We sit a couple of buckets under them, they flick the rainwater right into the buckets.

[mikereed100]

Originally Posted by stevensuf

A screen shot of his nav gear showed 49 degrees AWA, 69 Degrees TWA and 5.9kn boat speed with 15.9kn true and 18.9kn apparent wind speeds.


Adding leeway??? 5 - 10 degrees??


150 - 160 degree tack through the water?


Are they really that bad???

I suspect not, but a link to the video might help. There are a lot of factors that could be affecting his performance. Some, like sea state and current, cannot be improved upon. Other variables can. Are those the original sails? Sometimes manufacturers put the cheapest of sails on boats when they are sold. After a few years they can be very bagged out and windward performance is compromised. How skilled a catamaran sailor is the skipper? I have a friend with a Lagoon 40 who can move that boat quite well to weather. See the thread on light wind sail trim.

[akprb]

Do not sail to weather, rule one.

[AZUS]

We have an Antares 44i, which tracks better than the charter cats, Lagoons and Leopards, we used to sail. But it is not great. We can sail at 45 degrees AWA, which means 65+ degrees in TWA. That means upwind legs are often at least motor assisted (when motorsailing the sails give useful lift up to about 30 degrees AWA). I understand that cats wit daggerboards can do appreciably better, but there is no doubt that we either: a) choose routes with AW bean reach or lower, or b) use the motor more than we would in a monohull.

Frankly, that trade off is FAR more than worth it to us (we wouldn't sail half the year if we were living on a monohull), but it is a tradeoff.

[Cpt Mark]

Large cats often require engine assist to tack. I used to Captain a 55' performance cat and this was the case.

I have a 35' cat and can tack through pretty easily. The difference is the width of the hulls. Further out you get, more drag to overcome.

Lagoons and the like to me are built for the charter fleet. Lots of room inside etc to attract people to charter in groups. You can't make much money on your 1 million dollar investment if it only holds 2 couples vs 4. I'd rather look at a boat that is designed to cruise, not charter. It is 2 different concepts and results.

[Cheechako]

Originally Posted by stevensuf

I have been thinking of cat, mainly a lagoon 440, so been researching them a lot lately, heard some condomarans don't point to well, the same old story.

I came across a video on youtube, a guy beating into winds mid pacific on a FP Helia 44, complaining of just wanting to turn on the engines.

A screen shot of his nav gear showed 49 degrees AWA, 69 Degrees TWA and 5.9kn boat speed with 15.9kn true and 18.9kn apparent wind speeds.

Adding leeway??? 5 - 10 degrees??


150 - 160 degree tack through the water?


Are they really that bad???


Heard someone on here review a modern leopard 40 they chartered with similar rants.
So does anyone care to share the performance of their cats, preferably with pics of instrument readings to back them up?

I had the old school TPI Lagoon 42 with the deep keels. Even it was pretty bad. (The newer Lagoons are like condos comparatively. More windage, less bridgedeck clearance, fatter wetted hulls.) Better to crack off a bit for speed if the wind is blowing enough. Yeah, I'd say it could be 140 degree or more. What I discovered is fast idling the lee engine pointed the boat up maybe 20 degrees better on each tack! Making water, charging batteries and at idle you didn't even know it was running. That's the way to go.

With this method, if the wind angle got toward beating, on a day long trip, we kept up with our friends custom 48 Perry design mono. Arriving at our destination within minutes of each other.

[blubaju]

https://irp-cdn.multiscreensite.com/...rmanceTips.pdf
No, I do not receive any commission, but I build a Wilderness 1320 10 years ago and still sail it. Their homepage is quite informative:
www.schionningdesigns.com.au

[Tornadosailing]

I have a condomaran, and yes, they're pretty bad upwind. Like others have said, how bad is a function of several variables, including the skill of the sailor.

My particular condomaran has very flat hull bottoms compared to Leopard or Lagoon models. Similar sized stub keels, but not much rocker to the hulls giving me about a foot less draft.

In flat water and good wind I can work it up to 38 degrees apparent. But then I'm making pretty significant leeway as well, so that pointing isn't really doing me that much good. I buddy boated with Riley & Elayna on LaVagabonde for a day sail in Biscayne bay, and he was able to point a few degrees higher, but also made less leeway at very similar speeds. That's what happens when you have dagger boards. But then again, we have the same waterline length, and they have what seems like half the interior room. They also have significantly less load carrying capacity. It's all a trade.

[onavegador]

In 2006 I sailed up the Red Sea. With winds over 18 knts I had an angle of 120 degrees. The cat sailed most of the time on Autopilot and event I had to sail the double distance I felt very comfortable. No healing live aboard was easy, cooking not to complicated. I sailed singehanded and I sailed the same a year later on a 13m monohull but that was totally different as no comfort due to the strong healing and even with a crew of four I prefered to sail on my cat.
Btw. you know my cat.
fair winds
James