Are "Performance Cruising Catamarans" safe?

[smj]

Originally Posted by ozolli

There is also zero chance the Antares 44 lwl/bh is 11.2.

It’s 9.2 according to Multihull Dynamics

[Chotu]

What is Hcl? I assume hull centerline. But what is that?

that’s the only term I can’t figure out.

Looking through a bunch of websites, is that a typo?

Edit:. I found the multiihull dynamics calculator

had to guess on a couple things. 18,000 pounds is the absolute maximum displacement for this boat. It will be basically sinking if you are higher than that. I still went for a hefty 16,000 pounds even though I weighed in at 12,000 pounds the last time.

so I have to get this thing on one of the travel lifts that can accurately give me the displacement.

also it is early. It is a little chilly. I’m not getting out of bed to measure my bridge deck clearance. It is exceptionally high however. I guess that 48 inches. That’s probably too high.

***This is mainsail and self tacking blade jib only. No other sail area. kind of a lowest performance available figure. what are other people using for sail area? It seems like that could be very much open for debate.





here are the results.

[Factor]

At the risk of reigniting the spurious Ferraris are unsafe and crap box subs are the safest thing on the planet and will protect you in a nuclear holocaust debate - always remember you can reef on any boat, just like you can lift off the throttle on any car. But people who are to stupid to do that - well Darwin can look after them.

The other issue oft overlooked is the static stability may also be affected by the ability of a lighter boat to accelerate.

[boatman61]

Originally Posted by Factor

At the risk of reigniting the spurious Ferraris are unsafe and crap box subs are the safest thing on the planet and will protect you in a nuclear holocaust debate - always remember you can reef on any boat, just like you can lift off the throttle on any car. But people who are to stupid to do that - well Darwin can look after them.

The other issue oft overlooked is the static stability may also be affected by the ability of a lighter boat to accelerate.

A Skoda, one is prepared to drive anywhere..
A Ferrari one sweats about where one parks, let alone drives..
Might scratch the paintwork..

[lestersails]

Gotta say I am changing my opinion about our Antares fellow the more I look at this stuff. Just for curiosity, I looked up data on SailboatData.com

Disp Heavy Disp
From Video From Sailboat data
Outremer 452 10460 15984 -53%
Balance 526 19622 26896 -37%
Balance 486 19848 ???*
Gunboat 48 20921 17700 15%
HH 55 31136 31305 -1%
Seawind 1260 17808 18078 -2%
Privilege 465 27484 23000 16%
Leopard 45 32883 32849 0%
Antares 44 GT/H 22489 22500 0%
Xquisite X5 47040 39683 16%

His displacement numbers seem to be highly erratic. Four of them are essentially equal, two are off by 15% or so and two are way more than that. What gives?
*Note that sailboatdata.com did not have the Balance 486. I noted above that Matt cited the 482 - did he put the wrong model number in his table in addition to unreliable displacements?

[Chotu]

I still don’t see how any of the sail areas are calculated. I didn’t know how to calculate my own.

And are they using maximum displacement? True displacement?

I think that shows that all of these numbers are kind of wishy-washy.

Who knows what assumptions people are making when they fill in the parameters.

[skipperpete]

Originally Posted by chubby

with all due respect.. i'm not sure how anyone could suggest any 44 foot catamaran is anywhere near comparible to ANY 55 foot catamaran.
not even close in weight class.
not comparable in terms of size y loads involved..


for an actual comparable...
the same sized outremer as the antares 44 has a KSI of 25 knots. (!!)
meaning an unexpected 25+ knot gust could potentially turtle you...


ksi= more or less the wind spead where you can expect you can expect to capsize (with wind on your bean...and sails 100% up)



this is exactly why (some) of these "performance cruising cats" are NOT safe (for many)


(to be more precise)they are not appropriate(imo) for the typical cruising family that may want to relax on passages....




data for a lagoon 440..


i remember being informed that 50+ knot gust was enough to flip my old lagoon(never knew the exact data)


..so i know (err believe) it is possible to turtle a fat cat...
but does anyone have any links or examples of a leopard, FP, or lagoon getting capsized by a gust?(or nonhurricane wind)?
i searched google.. but could only find examples of the usual suspects .(outremers, marsaudons, gunboats, DIY one-offs..)

Well there was that one in the NZ westhaven marina video..... airborne and inverted... that pretty much settled any doubts I might previously have had.

[Matt Johnson]

Originally Posted by Chotu

I still don’t see how any of the sail areas are calculated. I didn’t know how to calculate my own.

And are they using maximum displacement? True displacement?

I think that shows that all of these numbers are kind of wishy-washy.

Who knows what assumptions people are making when they fill in the parameters.

In this example it is max displacement.

The sail area is:

The fore triangle -
1) 100% foot length from forestay to the mast
2) Height to forestay attachment point
3) Divide that by two.

and add mainsail area

[JustMurph]

Originally Posted by Factor

At the risk of reigniting the spurious Ferraris are unsafe and crap box subs are the safest thing on the planet and will protect you in a nuclear holocaust debate - always remember you can reef on any boat, just like you can lift off the throttle on any car. But people who are to stupid to do that - well Darwin can look after them.

The other issue oft overlooked is the static stability may also be affected by the ability of a lighter boat to accelerate.

Here here.

I'm not sure how there is even a discussion still going here.
a) The figures used in the video are nonsense
b) Every sailor on every type of boat needs to know when to reef their boat to sail conservatively.

We just reef earlier on the performance cat (and will still go faster than the condos with full sail).

As fxykty says, re-run the numbers on the reefed performance cats (which now have a much lower centre of effort) and you'll see they're perfectly safe.

[Chrisatlantic]

Exactly, by their own logic too.

Otherwise, anybody can drive a car off the side of the road, you just have to decide you’ll be the one to stay in control, keep the speed appropriate for the conditions and know when to take your foot off the gas.

Don’t think the way too safety is to put a five year old behind the wheel of a Volvo and I’m not ready to endorse dumbing my cars down to the point that that would be safe — I certainly am not ready to dumb my boat down to that point either.

[Chotu]

Originally Posted by Matt Johnson

In this example it is max displacement.

The sail area is:

The fore triangle -
1) 100% foot length from forestay to the mast
2) Height to forestay attachment point
3) Divide that by two.

and add mainsail area

That’s exactly what I did. I think my triangle top main is hurting me.

That will need to be replaced at some point soon.

Is that what everyone did though?

I find it hard to believe the gun boat 48 has so much more sail area than I do. Not without flying a screecher or something in the numbers.

[Matt Johnson]

Originally Posted by Chotu

That’s exactly what I did. I think my triangle top main is hurting me.



That will need to be replaced at some point soon.



Is that what everyone did though?



I find it hard to believe the gun boat 48 has so much more sail area than I do. Not without flying a screecher or something in the numbers.

I believe it is about the same sail area as the Mumby 48, so I can see it being pretty close.

[Chotu]

Originally Posted by Matt Johnson

I believe it is about the same sail area as the Mumby 48, so I can see it being pretty close.

I guess it’s the large roach main.

I didn’t think the triangle top would hurt me this badly.

Oh well. Full sailing performance will be at a later date I guess.

But looking at all the numbers, it’s interesting that using more foresail is a little bit more stable than the large roach main.

[Kinkircating]

Originally Posted by lestersails

Gotta say I am changing my opinion about our Antares fellow the more I look at this stuff. Just for curiosity, I looked up data on SailboatData.com

Disp Heavy Disp
From Video From Sailboat data
Outremer 452 10460 15984 -53%
Balance 526 19622 26896 -37%
Balance 486 19848 ???*
Gunboat 48 20921 17700 15%
HH 55 31136 31305 -1%
Seawind 1260 17808 18078 -2%
Privilege 465 27484 23000 16%
Leopard 45 32883 32849 0%
Antares 44 GT/H 22489 22500 0%
Xquisite X5 47040 39683 16%

His displacement numbers seem to be highly erratic. Four of them are essentially equal, two are off by 15% or so and two are way more than that. What gives?
*Note that sailboatdata.com did not have the Balance 486. I noted above that Matt cited the 482 - did he put the wrong model number in his table in addition to unreliable displacements?

Yep, the video is riddled with factual errors in the data, misleading information and is just comes across to the educated as a smarmy sales pitch predatorially targeting those who without experience. The sad part is I've met this guy, and he is super nice and seemed knowledgeable. Just sell to your strengths and acknowledge other's strengths in the process, could have been a decent video if he took a more honest and big picture approach that tells the whole story.

[Joli]

Originally Posted by JustMurph

Here here.

I'm not sure how there is even a discussion still going here.
a) The figures used in the video are nonsense
b) Every sailor on every type of boat needs to know when to reef their boat to sail conservatively.

We just reef earlier on the performance cat (and will still go faster than the condos with full sail).

As fxykty says, re-run the numbers on the reefed performance cats (which now have a much lower centre of effort) and you'll see they're perfectly safe.

The problem is always the same, an unexpected change in the weather. We have occasionally missed changes on multi day passages. The worst was 15 knots to 50 knots in 30 seconds, at night, in the trades, watching the stars. None of us saw it coming, knocked us down. One more caught us that evening, couldn't see it on radar, stars twinkling above us. It was very odd.