Multihulls- ?the way forwards.

[dralex]

I know there are a few multihull enthusiasts out there so here goes-

I think there is a big argument for the definative boat to be a multihull- I have only ever sailed on a Prout Event 34, which is alright, but a bit lumbering and heavy. If I went for a multihull, it would need to be significantly faster and more fun than a mono. I like the idea of shallow draft and tha ability to dry out. I nearly looked at an unfinished Woods Cat before buying my current boat, but it sold really fast.

My question is- which boats would people go for in the 32- 40ft range and which sail the best.

Just dreaming at present, but I know nothing about multihulls.

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[snowleopard]

if by 'sail the best' you mean fastest, you need to look at tris, things like the dragonfly range. they are capable of speeds up to say 20 knots.

nothing is for free so they are very limited on space and even more on load carrying. light fast multis become very unexciting when overloaded.

for a comfortable cruiser you'll get a lot more accommodation in a cat. you'll need to go for ,in 35ft for 2 people, 40ft for 4 to have the carrying capacity for long-term cruising while keeping the weight light enough to enjoy the performance.

few production cats fall in this lightweight category. as you know, prouts are pretty solid and it shows in their performance, no better than an equivalent length monohull. the french production boats are less heavily fitted out but still weigh in around 7-8 tons for a 40 footer against 5 tons for a one-off performance cruiser.

the big problem for a buyer is that there are no volume production lightweights so you need to search the brokerages for them or build your own as i did.

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[dralex]

Just to clarify- would want good living space for extended cruising, but also some performance with it, but do not want Formula1 performance- ideally looking for a middle ground. I'm sure a Dragonfly would be great for weekend sailing, but I do like my comforts. I saw a Beneteau Cat recently which looked fairly sporty, but don't know what it is and whether it really is sporty.

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[Ships_Cat]

Big move to cats in the recreational power boats in NZ and Australia, and in passenger vessels as well (and is so in UK as well for passenger vessels). Foil assisted ones as well.

Sailing cats are not so common down here in NZ (only one in our marina) and I think that is mainly because of the heavy conditions, but more common in more sedate tropical Pacific and Queensland.

Taking up Snowleopard's point on tri's, I know one person who is exploring the possibility of building a 60 m or so super sailing trimaran (superyacht class not race boat).

John

<hr width=100% size=1>I am the cat but I am only 6.

 

[dralex]

That would be nice- possibly a bit beyond my budget. There are also lots of urban myths about multihull stability and a 90degree angle of vanishing stability, but some of Richard Woods recent articles seem to dispel this. The main down side seems to be the slamming into waves.


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[Goodge]

I sail on my friends Solaris Sunstar which is a French design by ( I think) Eric Larouge.
This was built in this country by a firm in Weymouth who have now ceased trading, I don't know who ended with the moulds.

At 32ft she has two double aft cabins, a single berth forward and a pipe cot over the top to get to six. Separate galley, starborad hull, heads / shower/ bathroom portside.
Fitted out to a good standard for cruising she weighs 5.5 tonnes and has the larger rig intended for the 36 footer.

Performance is not spectacular in comparison to mono hulls but compares to about a 40 footer. Forget all the b*llocks about not going to windward, they do, you just sail them a little free-er. Go for speed not pointing ability.

I'm not an expert on the other multis but my friend took a course on and Athena 38 I think, and that convinved him it was they way to go. The Venezia is also very nice.

You do get a lot of boat for your money, but you wont get 10 knots going to windward but with a cruising chute up you'll probably get that off wind.




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[Superstrath]

I'm no cat expert, and was used to cruising a Moody 376. I've owned a Snowgose 37 for just over a year - a similar length to what I was used to. In general, it is faster. It is simple and undramatic to sail. It does slam in a chop, but you can live with it. It is very, very spacious, you can sit in the saloon and enjoy almost 360 degrees view, you can seat 8 in comfort, more at a squeeze. The galley is enormous, and the nav table can accomodate a full-size chart. The family love it - there is a ridiculous amount of deck space to lounge/play on, it does not heel, it has a dog-house so you can stay dry and out of the wind.
It took a bit of getting used to, but some reading and research pointed us in the right direction. It does not handle like a mono, it is tricky in tight spots, it is slow to tack, it has a huge turning circle. These things are not unique and just need experience, and are easily outweighed by the plus points.

Alistair

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[snowleopard]

comparing performance

here is a formula developed by derek kelsall for comparing multihull performance. the figure it gives is a fair approximation to passage average speeds but is really intended as a way of comparing different designs.

5 x sq root ( LWL x sail area / displacement)

units: feet & pounds

it is essential to use a displacement figure that represents the actual weight in cruising trim, not the dry boat quoted in manufacturers brochures.

there will be anomalies because it doesn't take into account important factors like hull beam. it comes out a bit optimistic for wide-hulled designs like catalacs and BO'Bs.

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[Talbot]

Re: comparing performance

Nothing wrong with a catalac speed unless you want to go windward!

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[snowleopard]

Re: comparing performance

got this from a catalac owner who told me that they have a wave-making hull form which gives rise to a hull-speed limit like a mono. the same is true of BOB's designs which are also hard chine and low hull length/beam ratio.

slim multis (l/b ratio 10 and above) keep on going faster as more power is applied and the formula is based on that assumption.

i don't know the stats for your boat - have you tried plugging them into derek's formula? i'd be interested to see what it comes up with.

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[Capt_Marlinspike]

For a really good value cat check out the Gemini. Ideal cruising boat for a couple.

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[dralex]

How about couple + baby+ labrador??

<hr width=100% size=1>Just enjoy it.

 

[Talbot]

Re: comparing performance

Formulae results are 5.52 kts

The biggest problem is ability to windward. The solent chop and the hull form are incompatible, and the catalac needs to keep hull speed up to minimise leeway. This is compounded by a small sail area (rather like the snowgoose) for example close hauled apparent wind increase from 15 kts to 18 will increase speed by 1 knot!

I went round the island this year in an unofficial 10.5 hrs (but wasted abt 50 mins at the needles) - the leg from the needles to St Catharines was dire, with wind and tide against, and I compounded this by staying further out in the tide flow to avoid the real racers. The hull form will plane, and have achieved this a couple of times, and am frequently in the 7-9 kt range. Not bad for a boat with a waterline length of abt 26 ft

Nobody has mentioned that UK cats are traditionally heavier than other countries (with the notable exception of the Woods and Kelsall designs) Thus the performance suffers, on the other hand they are also renown for their toughness in bad conditions, where as french designs are more perfomance oriented.



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[luddites]

Re: Multihulls, the way forwards, or sideways?nm

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[Talbot]

To answer the exam question of which cat in the 32 - 40 ft range needs a great deal more data. The biggest decision maker is money!

At the top end of the scale in cost terms, The FP Athena has a lot of supporters, and the new BroadBlue 375 deserves a look.

In the middle range of cost I would also be looking at a couple of the Woods designs - a 37' Flica, and the new Eclipse These tend to be at the faster end of the scale, but internal finish tends to be a bit more sparse.

At the lower end you start looking at older Prout 31/35/37' All of them worth a look.


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[Sybarite]

Suggest you look at this range. They have a good reputation in France as relatively simple, economical, fast cruising cats.

http://www.catamaran-outremer.com/index.htm

If you want to go to the top of the range: hi-tech composites; assymetric hulls with centre plates and (slightly) bulbous bows...

http://www.catana.net/frameset.php?page=home.php&lang=us&rub=1


John

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[boatmike]

While I sometimes agree with some of the things you say This time you are entirely correct! There are only three decisions you have to make 1. How much money have I got 2. How much money have I got and 3. Wanna guess.....
Yes Your choice for a cruising cat is good too although the Broadblue would be top of my list giving comfort, seaworthiness and speed..... Can't afford one though....

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[boatmike]

Re: Multihulls, the way forwards, or sideways?nm

Heathen! You will get me going on the insults again!!!

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[boatmike]

The reason most Brit designed cats (especially Prouts) are criticised for being slow is that they are biased towards seakeeping rather than speed. While you Kiwis can boast some seas you should be aware that the English Channel and North Sea ain't no millpond either. I can think of no boat that I would feel safer in than my Snowgoose Elite. Yes she slams in big waves, no she is not fast, but she is a cruiser and very very safe. She also goes to windward better than any other cat I have sailed in rough seas and does not need to maintain any more than 4-6 knots to do so due to her relatively high keel area. Most of the Aussie cats I have seen (and some that I have sailed) seem to be traditional very light displacement boats that rely on speed for windward performance and therefore go completely to rats in a big sea going to windward. All this relates to the question of cats under 40 ft as asked. Over 40 ft its a different (but very expensive) ball game and there are some very nice boats around from all over the world.

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[boatmike]

Re: comparing performance

This formula has no scientific basis any more than the old square root formula for monohulls does. Hull shape is everything. It's very easy to build a very light boat with skinny hulls that will go very fast. The trick is to build a CRUISING boat that will accept livaboard gear, a reasonable sized engine, stores, water, fuel etc. Put all this gear on a fast cat and it will become a very slow cat. Thats what Derek is trying to tell you with his formula. It does not work at all though for a wider soft bilged design with long low aspect ratio keels like the Prout designs.

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