cat vs monohull

[James]

Without stating the absolute obvious, what are the main differences between the two types of boat?
E.g. I've heard that cats do not sail upwind as well. What about tacking?
I also heard that with a cat, instead of reefing, one doesn't, the boat just goes faster.
Thanks if you reply

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[Goodge]

I sail regularly on a 32 foot Solaris Sunstar catamaran. It becomes obvious that monhull yachts tend to point higher going upwind. This is partly due to the cat having a wider sheeting angle for the jib / headsail. Additionally it is usually better to sail the cat a bit free-er going up wind, ie conceed pointing ability and go for speed. Tacking does take longer although we often back the jib to assist the bows round. As for reefing ,cats do indeed reef but maybe later than their monhull counterparts as they are not subject to heel like the monos. Having recently experiened 33 knots in France last Friday, I can say that there was a lot less drama going on than if we had been on a yacht.
However not all cats are as fast as you may think as some of the cruising cats can still be quite heavy and only achieve monohull type speeds when some people expect you to be sailing at 12 knots all day long.

Hope the above helps.


Performance of cats against mon

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[Talbot]

I bought my Catalac initially because wife and daughter did not like being heeled over. I would not now have a monohull. Older cat designs do not go to windward well, but new ones seem to, although not as well as a performance cruiser. Space inside a cat is much much better and normally you get very much more boat, but like in all things, every boat is a compromise so analyse what you want to do with your boat, and where, and then start to look

Once you have narrowed it down revisit this forum for comments on the different boats.

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[Scillypete]

Cruising cats will not go to windward as well as most mono's but in the right conditions and sailed reasonable well they will cover the ground quickly just don't try to point as high as the moan-oh-hulls.
I sailed a cat for seven years and she went very well to windward for a cat and more to the point I hardly ever used the engine unless there was no wind at all, if there was enough to ripple the water we sailed and often went past moan-oh-hulls that were motoring.
For some odd reason I got a seven year itch and sold it and bought a mono but after two seasons the family have given me an ultimatum, consequently the boat is for sail and we shall be returning to catamaran sailing, and I don't mind one bit, in fact it is going to be a real pleasure to get back on a cat, sail on the flat, tea cup staying put, loads of lounging space on deck, uncluttered storage space below (but don't be tempted to fill it all) the pro's are many and I could go on for a while yet but of course all of it is just my personal opinion.


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[steveh]

For more info get the book"Multihull Voyaging" by Thomas Firth Jones - ISBN 0-7136-4223-8.
You will find everything you need to know for succesful multihull cruising.
You do need to reef - sooner if a racing multi, about the same if a cruising boat. Much easier on a stable boat mind.

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[Sybarite]

The main contras seem to be (the pros have been stated by others - and I agree with them) :

Little or no feel to the helm and therefore less pleasure sailing.
Can't sail as close to the wind - but modern racing catamarans are getting much better.
Increased berthing and marina costs.
In ultimate conditions they flip, usually without much warning - but to their credit, they don't usually sink.
Conflict of weight carried against performance.

John



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[Scillypete]

In ultimate conditions I think you'll find there are more reports of mono's being knocked down and damaged, some to the point of having to be abandoned, than there are of multihulls being flipped and of those multi's that have the majority are racing boats. In those conditions it would imho be far more comfortable aboard a cat, I know which I would prefer to be on.



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[Jacket]

Of course, but thats because there are far more mono's sailing the world's oceans than there are cats. If you looked at the % of cats that capsized compared to the % of mono's that had to be abandoned as a result of being knocked down, it would be a very different story.

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[steveh]

Cats can turn over and Monos can sink - understand the risks and principles of each boat and sail accordingly. Judging a type of boat by what happens when you push it to extremes when racing is not relevent - this is where most of the reports of cats flipping etc come from.

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[Jacket]

I agree that you can't look at racing boats, but I thing even if you look at cruising boats, % for % mono's would come out on top if you looked at capsize versus sinking as a result of a knockdown.

I'd prefer to be knocked down and loose the rig, but have the mono still afloat, to a floating cat upsideown but still floating, as at least you can jury rig the mono and sail it home.

The big advantage of a cat as I see it, given the amount of rubbish floating around the seas nowadays, is that they won't sink if holed.

But cats will never suit me. I do most of my sailing single handed. Having experienced a coupkle of (scary) instances where the wind has gone from less than a F3 to a F7 in a matter of seconds, I'd never feel happy with a cat, as what happens if the gust hits when I'm down below or asleep?

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[steveh]

I can't see the advantage of a multihull if you singlehanding but I know of a few tris that are - don't know how they cope with with sudden gusts apart from just accelarating quickly. But then in a mono you could be layed over with the washboards out and have a problem with a mass of water entering!

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[Jacket]

For water to enter the companionway, most boats would have to be over well beyond 90 degrees. Wind alone will never knok a boat over this far- it would require a breaking waye to do this, and at least they take time to build up, giving you pleanty of warning.

I'd imagine most multihulls with full sail up and hit by a F7 gust would capsize, unless they were running at the time, and those that wouldn't capsize are probably so undercanvased that they'd be slower than a mono in normal winds.

May be wrong, having never sailed a multihull.

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[Boathook]

Re: cat vs monohull re Jacket

My cruising Cat goes sideways, shudders and accelerates when the wind gusts from F3 to F7. When broaching with a spinnaker in a F5 the same happens and she then goes back on course as if nothing has happened !!

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[Rohorn]

I sailed a Wharram around the Aegean for seven years then bought a Dean cat six years ago, and have had enormous fun out of both. The Aegean can be tough, with square waves and often the necessity to go to windward up narrow straights.
If my cats were more aerodynamic they would would go better upwind sail or power. Here the answer is to have enough engine power to get out of trouble, sailing niceties get irrelevant when it hits the fan. The french cats are more aerodynamic but those awful rigs with huge mainsails and three-stayed masts mean you almost never see them sailing, only motoring, around here. The Dean's mast is way back, like a Prout, so the small main is never reefed. The French cats have round convex aerodynamic cabin roofs to clamber around on so reefing can be downright dangerous. You never see one single handed.
Doing everything from the cockpit is a boon.
There is a thing about many Brit cats that they are built to go through the canals to the Med. When they get there they wish they were a metre or two wider.
I note many refering to loading problems. My Dean really doesn't seem to mind heavy loading, the hard chine slightly asymetric hull form being very forgiving. We did get twelve knots once in forty one knots of wind, but she's very often at ten knots in twenty knots of wind. Going into the waves is arduous, speed falls off fast, so some nice quiet power reliably in hand is very important.
Down below she's like a home, not like a boat. Nothing much is stowed away. That says a lot!
Cheers...R

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[extravert]

I would disagree with a F7 gust causing a capsize with full sail up for the multihulls I know. For my Dragonfly 920 the capsize windstrength for a beam-on wind onto a full sail area sheeted in hard is stated by the manufacturer as 45 knots, more like a force 9 than 7. The equivalent Corsair 31 is similar in sail area, beam and weight, so I expect would have a similar capsize windstrength.

Corsairs, Dragonflies and other trimarans are generally quicker and more powerful than equivalant sized catamarans, so I would very much doubt if a modern cat would capsize in a F7 gust with full sail area.

My boat doesn't really get going until a F5. Reefing occurs for me now at F6/7 (upwind/downwind), not F5 as it was on my mono. A gust of F7 with full sail up is not a problem. It's the combination of high boatspeed, high windspeed and high seastate where a F7 will become dangerous. This is not going to occur during a F3 to F7 gust.

<hr width=100% size=1>One day, I hope to own a real boat.