Light air performance of different multihulls?

[jmh2002]

Oh... Jimmy now sails for Luna Rossa Challenge, and Ben for Ineos Team UK. Oracle Team USA is essentially defunct these days.

[Cheechako]

Originally Posted by jdazey

Our threshold for turning on the engines varies on conditions. If we're on a tight schedule and have fuel, we can motor 8+kts. If there isn't a deadline and over long distances, we'll sail as much as possible. Our passage from Ensenada to Sitka was 2600nm+/-. If our speed dropped much below 3.5kts (4-4.5kts wind) I'd give it a half hour. If we're still dropping below 3kts, I'd start a motor. Main and jib only, no code/screecher sail, but I'd sure like one.

That's about my limit, 3.5 knots minimum. I have found in a cat if you just idle the lee engine in light air and motorsail the boat trucks along nicely pointing a good 15 degrees higher also.

[Factor]

Originally Posted by mglonnro

I vote for Jimmy Spithill, Ben Ainslie and the rest of Oracle Team USA to sail the heck out of a Lagoon 42 in light air conditions! Spectacular.

I always chuckle when I read Oracle team USA. Being lead by an Australian and an Englishman.

[wingssail]

Originally Posted by mglonnro

I scraped together ROUGH numbers from the posts in this thread. I'm sure I misinterpreted something, but it's easy to fix.

"How much wind is needed to get about 4-5 knots of boatspeed?"

Upwind

Balance 526 4-5 knots
Outremer 5X 5-6 knots
Shuttleworth Advantage 6 knots
Gemini 105MC 34 foot 6-8 knots (?)
Serendipity 43 7-8 knots
Seawind 1160 Lite 8 knots
Hanse 388 8-10 knots
MainCat 41 9-10 knots
Lagoon 400 9-10 knots
Lagoon 42 9-10 knots
Lagoon 42 TPI -93 10 knots


Reaching

Shuttleworth Advantage 4 knots
Schionning Spirited 480 4-5 knots
Balance 526 4-5 knots
Outremer 5X 4-5 knots
MainCat 41 4-5 knots
46’ Custom Cat 4-5 knots
Searunner 38 5-6 knots
Lagoon 42 TPI-93 5-6 knots
Lagoon 400 5-7 knots
Hanse 388 6-7 knots
Gemini 105MC 34 foot 6-8 knots
Lagoon 42 8-9 knots

These numbers are interesting but not too useful. For good comparison we need polar diagrams (from the designer, manufacturer or a rating organization). Here are mine (two examples). For upwind and down wind VMG is the key. Sorry, for the purposes of this thread they are not for a multihull.

My boat can go 5-5.5kts in 6 knots of wind. My VMG will be 3.5 knots @45 deg TWA.

This is slow for us, we really come alive in 7-8 knots of wind as the polar shows.

My source has 8200 examples of Monohull Polars, only 8 examples of Multi hull polars.

[Factor]

Originally Posted by wingssail

My source has 8200 examples of Monohull Polars, only 8 examples of Multi hull polars.

And yet you are posting it in a thread talking about Multis and in a multi forum area

[mglonnro]

Originally Posted by Factor

And yet you are posting it in a thread talking about Multis and in a multi forum area

Well, for me (monohull considering moving to multihull) this comparison is of great interest as well.

I could rephrase my own original question like this: if I want to have noticeably better light air performance, what would be the least expensive multihull upgrade from our present boat?

[Mr B]

Originally Posted by mglonnro

Well, for me (monohull considering moving to multihull) this comparison is of great interest as well.

I could rephrase my own original question like this: if I want to have noticeably better light air performance, what would be the least expensive multihull upgrade from our present boat?

Possibly a Gemini 105MC,

[Tupaia]

Originally Posted by mglonnro

Well, for me (monohull considering moving to multihull) this comparison is of great interest as well.

I could rephrase my own original question like this: if I want to have noticeably better light air performance, what would be the least expensive multihull upgrade from our present boat?

OK so we know what kind of girl you are, it's all down to the price. How big a multihull do want? What is your planned useage?

In the smaller cat-egories there are some nice fast options that are relatively inexpensive.

https://www.multihullcentre.com/dazc...e/dazcat-1095/
Sailing Catamarans - Sagitta (MI)

This little 30ft cat will leave bigger monos in the rearview mirror, probably one of the most fun boats I have sailed on.
"Conclusion

Overall the Sagitta proved a comfortable boat at sea with an easy motion even in the prevailing lumpy conditions and easily ran up to 14 knots on a reach despite not increasing the sail area once we came off the wind. She tacked positively in the open sea and handled easily under power. The accommodation plan provides exactly what the Woods intended so that altogether she makes a very attractive boat"

[wingssail]

Originally Posted by Factor

And yet you are posting it in a thread talking about Multis and in a multi forum area

Factor, the OP is a monohull owner and his original post was unclear, at least to me, so that was an honest mistake. Since then several posters have engaged me and others in the broader topic. And since his recent post showing the light air capabilities of several boats included my monohull, I think it is reasonable to think that the conversation has expanded.

I don't feel threatened by multihulls and I am genuinely interested in the light air and upwind performance of modern performance cats. I already know from plenty of experience the capabilities of typical cruising catamarans, I see them all the time and sail against them frequently, in organized events and in ad-hoc hook-ups. And I know from other experiences that passages times are not much different from other types of vessels.

But the bigger, faster, cats that might combine speed with with some true liveaboard possibilities interest me. Can they really make good VMG to windward? How good are they in light air? Are they safe in really big storms? Can cruisers keep sail area up at night? How about storage and capacity to carry provisions, spare parts, extras sails, extra anchors, long chains, etc.

So don't try to bully me, please, into going away. I don't think I am a threat to you.

Now, talk is cheap, lets see some polars.

[Training Wheels]

Originally Posted by mglonnro

Well, for me (monohull considering moving to multihull) this comparison is of great interest as well.



I could rephrase my own original question like this: if I want to have noticeably better light air performance, what would be the least expensive multihull upgrade from our present boat?

Trimaran

[mglonnro]

Originally Posted by wingssail

Factor, the OP is a monohull owner and his original post was unclear, at least to me, so that was an honest mistake. Since then several posters have engaged me and others in the broader topic. And since his recent post showing the light air capabilities of several boats included my monohull, I think it is reasonable to think that the conversation has expanded

[...]

But the bigger, faster, cats that might combine speed with with some true liveaboard possibilities interest me. Can they really make good VMG to windward? How good are they in light air? Are they safe in really big storms? Can cruisers keep sail area up at night? How about storage and capacity to carry provisions, spare parts, extras sails, extra anchors, long chains, etc.

The OP is interested in all boats and have the same questions you mention above.

I'm inevitably comparing the multihulls to what I'm currently sailing myself, a monohull, and it's certainly interesting to compare to other monohulls as well.

Above all, I want to move quicker than now in light air, and it seems there are quite a few multihulls that can do that

Peace.

[Training Wheels]

Or proa!

[mglonnro]

Originally Posted by Training Wheels

Or proa!

So trimaran or proa. Any specific models in mind? For six humans and a dog, CE A (capable to take us from Finland to the Bahamas).

[Training Wheels]

A big one.

[barnakiel]

But these fast light wind ones how do they sail? AP and RC?


It starts with the crew. And very few skippers / crews can sail in light winds.


One must start with a light boat in light winds. A Laser maybe on a lake or similar stuff.


Only then one can go on a Lagoon and try to use the existing knowledge.


One cannot learn sailing in light winds in a boat that does not sail well in light winds. At times, does not sail at all in light winds.


99% cruisers motor in light winds, cat or mono.


Light wind performance is for those who started early and visited the sea.


b.