Multihulls

[mystymike]

Hello.
On following the web prompt by "TALBOT", in the thread on 3-5-04 "Buying a small family cruiser", I found myself on a mutihulls for sale site. Having looked at the craft on offer and further 'lightly' researching multihulls I have concluded that this is the type of sailing I want to pursue (moderate heel and fast with safe grounding when required). I have read "Jools-Topcat", web pages and found them very entertaining and informative.
Questions:- (1) What are the advantages or disadvantages with owning a Catamaran or a Trimaran.?
(2) Does a Catamaran sail better or the same as a Trimaran.?
(3) What is the learning curve timetable.?
Thanks. Mike.

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[Courageous]

Mike - general considerations are:

For any given length of vessel a Catamaran is likely to provide you with more accomodation (depending on the size of boat you are looking at buying) since accomodation is likely to encompass the total volume of two hulls and the bridge deck area. Some larger Cats like the Prout Snowgoose also provide standing headroom in the bridge section making for a vastly increased accomodation. A corresponding Tri is likely to have accomodation only in the main centre hull and so is little better than a mono in this regard. This leads me on to my next point:

Costs wise, if you are thinking of residing in a marina or visiting one regularly then you must remember that almost universally marinas consider Cats to be 1.5 times the length of a monohull when applying the berthing fees. Not sure what the deal is with Tri's but you can expect it to be at least the same.

Handling wise I haven't done any Tri sailing BUT have a goodly amount of sailing experience with mono's and cats. I should have thought that Tri's MAY haul to windward a little better than cats but would bow to the expertise of others in this regard.

Learning curve"£$)*&&.....???? How klever ARE you? What kind of experience do you have to date? If you are new to sailing I generally maintain that if you are of average intellect and fit, able and above all else keen then a day's course should give you the basics to be able to sail in protected waters without too much trouble. Take on one of the many competent crew courses around and that would give you a very good grounding. As for the rest - well we keep on learning every time we look at our bank statements!

Hope this is of some value and good luck! Above all else enjoy! There really is no better life IMHO........

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[Talbot]

<font color=blue>Advantages of a cat</font color=blue> - Much more space internally for people and stowage for footprint of boat. naturally each model/class will have differing characteristics. The older designs are heavily built, and thus not as fast as they could be, or as good to windward, but much safer (due to their inherent strength)
Work on foredeck is MUCH safer due to space. When people are below and you are working to windward, you are not leaning over, and on a lot of them the helm position is on the same level as the saloon. When running before the wind the cat will stay absolutely upright (none of that horribly pendulum motion)
<font color=blue>Disadvantages of a cat</font color=blue> - performance to windward is not great so make sure that the boat has a decent engine (better with two as manoeuvring is so much easier). Do NOT be tempted to get a cat with daggerboards unless you always plan to sail with lots of people/race. <font color=red> IMHO daggerboards are extremely dangerous in a short handed cruising cat.</font color=red>
<font color=blue>Advantages of a Tri</font color=blue> - Fast and Very much better performance to windward. The ones with folding wings are cheaper to keep in a marina, but otherwise they tend to be wider than a cat.
<font color=blue>Disadvantages of a Tri</font color=blue> - Less space than even an equivalent monohull let alone a cat, thus work on the foredeck can be a nightmare as they can be very narrow there. Unless they have folding wings they take up a lot of space for very little accomodation space, and are thus expensive in a marina.

IMHO Tri are not the best bet for a first boat. If you were down Portsmouth way I would take you out to see what a Catalac is like.

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[simonfraser]

Hi,

a catalac is a nice floating caravan if that is what you want, hirondell is small cheap and sails well, be carefull with the dagger boards, good way to tip a cat.

without daggers you are very very very unlikely to tip a cat.

prouds are supposed to sail ok.

come and sail my strider cat, essex if you like.

Simon

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[Neal]

Here\'s a book you should read..

'The cruising multihull' by Chris White.

Its full of sound advice, good argument and generally useful information.

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[William_H]

I had a cat for some years then went to a lead mine (monohull) The thing I like about a monhull is the forgiving nature in a blow. It just leans over like a big spring. It tells you in no uncertain terms that you need to shorten sail. A cat just goes faster and better until without warning you are in big trouble with a capsize or mast failure. You need to be very judicious in managing a cat cos only you can guess when you are in danger. Secondly I do love the way the monhull will claw to windward. The cat I had did not go well to windward and using an outboard engine it could not be driven to windward due to pitching lifting the prop out of the water and the huge frontal area giving wind resistance.
Cat lovers will defend them and I do like cats in my case other factors like having a trailable yacht and being abler to race at the local club were other pluses. regards ole will

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[bendyone]

Hi

We had a 9m Catalac for 11 years, very safe and plenty of room, ideal for family holidays and crusing but dont expect to get anywhere fast. Off the wind f4 and above sails well, when into the wind good thing we had twin engines.

Have now gone back to a monohull for real sailing.



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[snowleopard]

\"dont expect to get anywhere fast\"

there's a tremendous range in the performance of multihulls. catalacs are heavy and come near the bottom of the scale, flat out at 6-7 knots. at the other end is the featherweight dragonfly which can hit 15-20 knots.

to get an idea of the performance of a multi this is a useful formula:

sq root (lwl x sail area/displacement)

units are feet & pounds, the result gives an overall figure which lets you compare boats, it is roughly the speed average on all points of sailing in 10 knots of wind

another formula gives speed under power:

sq root (lwl x h.p. / displacement tons)

this is pretty accurate but should not be used for boats with wide hulls like bill o'brien's or catalacs which have monohull-style 'hull speed' limits.

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[extravert]

Re: \"dont expect to get anywhere fast\"

Your formulae do not give results that are anywhere near realistic for me. Have I done the sums correctly?


lwl=28.7 feet
sail area=597 square feet
displacement ~2 tons

Sailing speed with 10 knots wind...

square root (28.7 * 597/ 4400) = 1.9 knots

I would hope to average more than 2 knots in 10 knots of wind.


Motoring speed...

square root (28.7 * 9.9 / 2) = 11.9 knots

My maximum speed under power is 7.5 knots




<hr width=100% size=1>One day, I want to be a real sailor. In the mean time I'll just keep tri-ing.

 

[extravert]

Here's some information on sailing tris.

Disadvantages

They are very expensive to buy for what you get.
There are not many manufacturers.
There are few for sale second hand.
They don't go well in very light airs.
Space inside is restricted by narrow beam.
They have low load carrying ability.
Non-folders may be difficult/expensive to berth.
Spares and repairs are expensive.
Their motion will be livlier than a similar sized mono.
Because of added sailing speed, they can be cold and wet.
Hitting a wave wrong to windward can slow them dramatically.
High apparent windspeed gives sails and rigging a hard life.
They need to be sailed sensibly.

Advantages

They outperform everything of similar size on all points of sailing*.
They accelerate quickly.
They don't lean over much.
They are light on the helm.
They float in very shallow water.
They can be dried out.
They are the most fun you can have with your oilies on.

The only other comment in this thread that I am dubious about is Talbot saying that foredeck work is a nightmare. Not as spacious as a cat agreed, but it's no worse than a level monohull. They are not that narrow up front. And also why go on the foredeck anyway when there're acres of space out the side for jobs like launching the spinnaker and sunbathing?

* Tris sail as close to the apparent wind as similar sized monos. They don't have great tacking angles, because increased boat speed hurts true wind angle. However, their VMG to windward still exceeds similar sized monos.

<hr width=100% size=1>One day, I want to be a real sailor. In the mean time I'll just keep tri-ing.

 

[snowleopard]

ok, let\'s try that again...

the formula i gave provides a comparison ratio, to get a figure related to speed, multiply the result by 5!!

i.e. 5 x sqrt (lwl x s.a. / disp lbs)

which gives you 9.8 knots which is pretty quick by anyone's standards!

(just read your profile - makes sense now!)


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[petery]

I sail a 'traditional' long keeler but have crewed in a friend's Bobcat and Iroquois.

Both great fun with masses of space on the foredeck and in the cockpit - but at 6ft tall I just cannot get used to kneeling at the chart table

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[Birdseye]

Some of what you read above is accurate, some inaccurate and some is generalisation. There is if anything greater variability in multi performance than there is in mono. So tell Connors that a cat wont go to windward when he thrashed that much larger NZ mono in the Americas cup. Of course they can - if you get the right one. And thats the secret - chose the multi for the useage you plan.

Most cruising cats are made reasonably safe from capsize by fitting low profile keels and short rigs. This tends to make them slow in light winds and prone to leeway. In practise, something like a Prout will make to windward as well as a Westerley bilge keeler until you get to the sea conditions where weight and momentum count in the Westerlies favour. Then its change direction or on motor in the cat.

On other points of sail you can expect that you will make maybe 15%to 20% better average speeds that the bilge keel mono. You will still not beat the cruiser racer mono unless you get a daggerboard type cruiser racer cat - say a Banshee or something like that. But then you have lots of sail and a style of boat that requires good handling at all times. It wont tolerate bad handling in the way most monos will.

At the other end of the spectrum you get boats like Catalacs. Not good sailing boats imho - more the floating caravan, though they will go quite well downwind.

The ride in a cat is way better than any mono I have sailed - do not underestimate the benefit of reasonably level sailing once you are out for more than an hour or two. Food preparation, going to the loo, working on deck - all are much easier. And deck work is definitely a lot safer as a result.

In 7 years of ownership and sailing all of the southern UK coast, I have never yet paid any extra in marina fees for my cat. OK I have sometimes had to argue, and in France and Spain I didnt always win. But here in the UK I have never once paid, but my beam is less than 15ft. A big fat French cat would probably be different.

And I have never felt at the slightest risk of capsize either. Of course you can capsize any boat (a cat takes more energy to capsize that the same length mono - basic physics) and the cat will stay inverted. People say it will be a floating life raft - maybe, but it will be constantly washed by the sea so dont plan on sitting in the dry on an upturned boat.

Weight is an issue with multis. Their performance advantage comes in part from light weight. A cat has plenty of space - let swmbo fill it with clutter and you will sail like a brick privvy. And weight goes with comfort if you are long term sailing. Lots of water, for example. So the space is misleading - you cant carry as much in the 35ft cat as you can in the mono despite greater space.

A tri will sail better and (with a daggerboard) point higher that an equivalent cat. But space will be worse than even the mono, and beam will tend to be more of a problem,. I have sailed a Farrier tri and it is a fabulous sailing machine. Way better performance than my Prout, but even at over 30ft it is little more than a day sailer IMHO.- or should I say in the opinion of SWMBO.

Finally, cruising cats arent usually a lot of fun to helm. Lack of heel might be an advantage but it also means less feeling of speed. Its difficult to describe, but its just a less tactile experience than a good mono or tri. So you put on the autohelm, and sit down and read - or anything else you can think of!

Personally, for longer term cruising I would get a cat every time. For day sailing and the occasional club race, I would buy a good mono. For boy racer sailing, and the sheer pleasure of literally being able to sail in a circle round a racing Sigma 33, I would chose the Farrier or Dragonfly. Yee-ha! /forums/images/icons/smile.gif

<hr width=100% size=1>this post is a personal opinion, and you should not base your actions on it.

 

[alahol2]

Birdseye has got it just about right. Our first multi was a 26ft Telstar, relatively cheap but sails fabulously for the money and the best fun I've ever had in a sailing boat. A tri tends to let you know when it's overpowered. Second multi was an Iroquois which will beat any cruising boat of the same length to windward even if it doesn't point as high. Great accommodation except for a 'stooping' bridge deck cabin. No real feel when sailing so the autohelm gets more use. Unparalled sunbathing space/play areas for the kids. Finally have recently moved back to a mono (Stag 28) because more and more marinas etc are trying to charge 'time and a half' particularly for winter storage. I wanted to get back to the enjoyment of 'feel' in the sailing, something a little smaller for ease of maintenance and finally a 'proper' wooden ships cabin for that cosy feeling early and late season when at anchor. It's all a compromise...

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[Richard_Woods]

As a start I'll say that well designed multihulls DO go to windward. I guess you've read the Eclipse boat test in the May PBO. In it David Harding reported that in the Round the Island Race Eclipse beat Mumm 30's to windward in 20-25 knots of wind. Most people consider the Mumm 30 to be a fast windward sailing boat.

So, not all multihulls are the same, indeed, not all monohulls are the same. A Catalac is the multihull equivalent of a Colvic Watson.

Unlike a Mumm 30 though, the Eclipse is a real cruising boat. Since the R the I race I have sailed mine from the UK to the Caribbean, Bahamas, the USA east coast as far north as Maine, and back south to Cuba and Belize. It is now in Guatemala.

Next, my boat has daggerboards. I like them even for cruising as they form the ultimate echosounder. They are a bit more bother and are expensive, but the boat is a better sailing boat with them. A LAR keel catamaran doesn't point so well, it pitches more and is slower off wind. A catamaran that relies solely on its hull shape is neither manoeuverable nor fast.

You can see much more about my Eclipse, about multihull design in general etc at www.sailingcatamarans.com


<hr width=100% size=1>Woods Designs for quality sailing catamarans
www.sailingcatamarans.com

 

[Jools_of_Top_Cat]

It is always nice to see manufactures and designers join the forum, welcome.

I hope you will stick around for us end users of catamarans and trimarans to be able to pick your brains from time to time. You may even be able to convert us over to woods designs if we decide to change our current vessels.



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