Fast Cruising Catamaran

[freetime]

Originally Posted by Mark424

I like Chris White's Atlantics, there is a new 42mkII, also 46, 48, 55
You might also look at the Maine Cat 30 & 41. I think the stats on the 41 are close to Chris White's Atlantic 42.

If you want fast, also consider a tri, a used contour 50, or Hammerhead 54 will really fly.

2 contour have been for sale in us for long time. Tried to find a hammerhead for sale, but i think it is under 5 built. If i should keep the boat for very long time i could go for a tri....but the second hand market if you compare to the price is not so good i thinkg. Also a big Dragonfly 1200...but they are expencive.
I will check the main cat 41......dont know about it.

Chris White have many things i like, but i did not know they was so fast. I know they are expensive.

[freetime]

Originally Posted by ldrhawke

Wich Chris white is this from....this is what i want

The BR 65 mono, did 13 knots in that wind as best, in 3 meters waves...

[Even Keel]

YouTube - high speed catamaran sailing

Outremer 45 voilier occasion

straight in your budget.
I get friends who did a direct atlantic crossing from Las palmas to St Lucie in 10,5 days (approximativly 12knots average).

[Tropic Cat]

Originally Posted by rigamarole

This is a good thread. I've been meaning to ask about Bruce Numbers. I did a google search for them in CF and got a whole lot of the old catamaran arguement threads (which thankfully have diminished). How do you figure out the bruce number again?
And, do any of you recall a thread where bruce numbers where tabulated?

If there isn't one, maybe we can start one. I have the latest Cruising World "Catamarans by the Numbers" issue and could figure those out, then add from there.

From my web site:

The Bruce Number is a power-to-weight indicator for relative speed potential for comparing two or more boats. It takes into consideration the sail area of the main and jib, no overlapping sails, and the displacement. Chris White, "The Cruising Multihull"; 1997 International Marine, Camden, Maine, states that a boat with a BN of less than 1.3 will be slow in light winds, and a boat with a BN of 1.6 is a boat that will be reefed often in offshore cruising.

Derek Harvey, "Multihulls for Cruising and Racing, 1991, International Marine, Camden, Maine, states that a BN of 1 is generally accepted as the dividing line between so-called slow and fast boats.

Bruce No. = SA^0.5/(Displacement*2240)^.333

[Palarran]

Thanks Rick. Can you remind me what a carrot ^ is? Sq root?

[Eleven]

the ^ is squared. So ^0.5 is the square root of and ^0.33 is the cube root of.
Spreadsheets should handle these just as typed in the formulae.

[Eleven]

That gives my Prout a figure of 0.955 which sounds about right.
That's 350 sq ft and 5 tons.
A reasonable indicator.
For a speedy cat I'd be looking at mast height to w/l length and the slenderness of each hull, beam to w/l length.
There's a thread somewhere on power in sailing cats. Planing or lifting a hull isn't for cruising, the hulls need to be fair, (no ripples) slender and free of added lumps.
If I drop the weight to bare boat 3.5 tons I still only get a figure of 0.99 which doesn't seem to be quite right. Since my hull speed seems to be 7.2kts by the log then if you really want PERFORMANCE then those slender hulls will really help to cut through the waves, and to pierce more waves, and to do that eveer so graceful pitchpoling. You choose!
Also consider pounding at twenty knots. You'll need clearance and a nacelle under the bridge deck but length is what will really count.

[freetime]

Ok.... alote of info. But

How to compare a Outremer 45 with a Outremer 55 Light? How big is the difference in different windcondition.

What i can see the outremer 45 is not so much slower than the 55, i understand that in big waves the 55 is faster. But if we take strong winds???

And the boats i can see with this slender hull is....
outremer, freydis, chris white and the maine cat. I have not compared the weight and sail yet.

What is the limit for a catamaran in this style without a big surf...in speed??? is 25 knots possible in a 45?

And i know i dont want to sail close to the limit when cruising but so i understand HOW fast they can go.

[Tropic Cat]

Are you looking for a big Hobie Cat? Narrow hulls can't carry necessary gear to go cruising and are little more than day sailors.

This is from a new page I've been working on . Dealing solely with catamaran design. It's pretty complicated and should be done in a week or so and posted to my website.

Length/displacement -ratio - LDR


Fully loaded displacement - mLDC

mLDC = 2 × BWL x LWL × Tc × Cp × Cm × 1025 (density of sea water)

Maybe I should put a link to what I have so far. This doesn't make much sense without the explanations.

http://catamaransite.com/catamaran_h...ensioning.html

easy on the criticism.. it's a work in progress and these things take time.

[Eleven]

A factor in this is how fast would you want to drive a big pickup across country, or a big lorry for that matter. Racing crews expect bruises all round and broken limbs occasionally. Are you cruising or insane? 25kts? Along a dry river bed. Take a speed boat ride sometime and make it a three week trip.
200 mils a day is good cruising, 300 is unusual, more than that is racing. The sea is rarely flat.

[neelie]

Freetime : If you read the attached article by Evans and Starzinger, the reality of consistently attaining 200 miles a day, every day is surprisingly infrequent. (200 miles a day is only 8.33 kts average.) OK the article is mainly for monos but it will apply to cruising cats as well - and for sure they are not double the speed of a mono.

Your 25kt requirement for a cruising cat is a very expensive option. A large fully crewed ultra light catamaran = $$$$. It makes a Gunboat look cheap. Of course it is possible, but I doubt anyone who contributes to this forum can afford one.

Of course I agree that slow is not fun. However, the promise of unrealistic speeds is only a marketing tool - there are other more useful attributes for the cruising catamaran.

[scrumble]

Originally Posted by Tropicyachty

I too am looking for a Cat, really leaning towards Outremer or perhaps a Catana. The Gunboat steering is just to strange, I like the vieww from an aft cockpit.

What view???

[freetime]

YouTube - TS50 XLcatamarans

The video with the Xlight TS50 or the attached Soubise/Freydis "Gifi".

The TS 50 2006 is for sale at 415000 euro + vat.
The Freydis 350 000 euro.

And this is what i want, a boat capable to 25 knots. And i know i dont cruise in 25 knots. But a light boat that can handle some sea and winds. And the interior, yes i want to sleep in it, but i dont need the lagoon bedrooms. I will do many shorter trips and perhaps some races to. Atleast what i want now.

And i will also take a look at the Aerofleet 45.... That is a Very light boat.

And i will not sail with 5 children....atleast not this year

And we have plans to put it in a company, but i know a fast one is expencive....

[freetime]

Originally Posted by scrumble

What view???

you can use your plotter with ais and radar, then you see "everything"

When do you put your 44a in the water???? looks so good....

[Intentional Drifter]

You would put a boat like this into charter? My, aren't you trusting.

ID