Multi speed/length relationship?

LOL Yep.

I could make a case that a greater number of mono's have sunk at their moorings than multis that have capsized at their moorings, therefore multis are safer ...

It is my *opinion* that you have to make a bigger error to capsize a multi than to sink a mono.

The multis capsize / monos sink argument comes from people that feel they have no responsibility for their boats. Boats do not capsize by themselves, after the error that caused the capsize, it comes down to the safety of the vessel after the event. The chances of swimming after the capsize are higher in a boat that can sink compared to one that cannot. This is simple stuff.

 

Bigcat and Teddy,

Optimum beam/draft ratio depens on displacement too. For a very light catamaran BTR 2 is good, but the heavier the boat the smaller the optimum BTR.

Here is an other, 10 m cat comparison. At very light catamaran under 2 tons, the optimum BTR is 2. At average, 2.9 ton, the optimum BTR is 1.3 and at heavy cat, 4.3 ton, optimum BTR is below 1.0. So in practice, heavier catamaran hulls are too narrow, if they are made optimum.

Calculation is valid at Froude number 0.6.

Terho

 

Can't agree with this. There are hundreds of things that can sink a mono, from knockdowns to failed through hulls, faulty exhausts, broken rudder shafts, keels falling off, propellor shafts falling out, collisions.....

Monohulls can sink in zero wind, sitting in their marina berths. (I've seen it)

A multihull will not capsize in those conditions.

 

In general, I have to have some sort of hard evidence to believe anything. I know of no evidence suggesting that multihulls capsize more frequently than monohulls sink; therefore I do not believe it.

However, I'm willing to base an opinion on speculation, but that speculation is accompanied by several caveats. In the first place, we need to define the kind of boat we're talking about. We're not talking about beach cats, because although these do capsize readily, it's not a tragedy when they do, since they can be righted by crew without outside assistance. Let's exclude small unballasted monohulls also, because although they capsize even more readily than beach cats, they usually have flotation and don't sink. I would also exclude racers from my speculation, because the price of speed is accidents-- this applies as much to monohulls sinking as to multis capsizing.

So, when I say I think multis capsize less frequently than monos sink, I'm talking about cruising boats. It's pretty hard to find a report of a well-designed multihull cruiser capsizing-- unless the boat is being raced and so is being pressed well past the edge of safety. It isn't difficult at all to find reports of cruising monohulls sinking.

Now, to muddy the water further, there are monohull cruising boats with enough flotation to keep them from sinking-- and for that reason a lot of folks think these boats are the safest cruising boats. But I disagree, though they can recover from a capsize, and will not sink. There are more hazards to the safety of sailors than sinking and capsizing-- in fact these cause only a small percentage of sailing fatalities.

The single greatest cause of boating fatalities is man overboard, and here, I think, the multihull has an enormous edge, because it sails flatter and is vastly more stable. The wide decks provide a lot of good safe workspace-- a lot of monohull sailors are lost when going forward to work at the mast or the bows-- whereas the multihull sailor is less likely to go overboard if he loses his footing-- he has a lot of deck to roll across before he reaches the lifelines.

Ray

http://slidercat.com/

 

Except, they're not. I'm talking about risk, as in "odds", not talking about whether it's possible with both hull forms.
Your argument goes like this:
A can acheive B
X can acheive Y
Thus A and X must have equal chance. well, they don't.

True, but you willfully neglect the chance/risk of "operator failure", and you certianly willfully neglect to compare the two.

So? There's not one case of "single" motorcycle accidents without human error (too much speed, too much leaning etc.", yet, a motorcyclist is more prone to have a "single" accident.

Ah, yes. Great! You need to pull in racing designs to cover you arse. Well, how about some real designs? Or, wait, even if it's true with racing designs, how do you figure you can extrapolate that to monohulls and multihulls at large?
Seriously, you consider a racing monohull with a hydraulic keel and water ballast an average monohuller you can simply extrapolate to monohullers at large?
Come now, you can't be serious (I hope).

Could you now? Well, in this instance you might be able to, but again, you're twisting the real world, making a strawman argument. Even if you DID make that case, it's far from being the case that monohulls sink more often than multihulls capsize.
Pleae get that right.

Wow! You must really think that mono's sink a lot!

Again: Wow! You are serious: All sorts of speculation, intertwined with extreme opinion and conjecture. That's really nice going – especially considering that you, the defender f multhulls, rhetorically try to defend multihulls by dismissing capsizes, stating capsizes _only_ happens to "people that feel they have no responsibility for their boats".

Now, how about backing some of these things up?

Ah, yes. because the numbers matters. One can take anything, and if the numbers match, it MUST be the same.

Seriously, one cannot simply count imaginary things that can go wrong, without also looking at the likelyhood. And that is what you're doing. You're finding every hole in a hull, stating that that can cause a sinking. Yes, of course it can, but we were talking sinking _risk_ (likelyhood) vs. capsize risk. And not whether what holes to be sure is up to hard wear and tear. I know racing machines have lost a lot of keels lately, but how do you think those machines matters in the big picture? Most boats and ships are monohulls, so those racers really doesn't matter. And in real life, not just statistically, they have absolutely no bearing on anything.

However, if you insist: How often you figure racing multihullers capsize? The racing fraternity certainly capsizes quite a lot. You actually think that part of the sialing community capsizes less than monohulls sink? Please, get real!
Oh, that's right, that simply "human error", so we'll disregard that, right?

You cannot seriously think that's a real comparison, can you?
















And when you're done with all that, please read post #53, last paragraph, five first words.

 

It's a real life situation. A monohull can sink in dead calm conditions. A multihull at least needs SOMETHING to push it over.

As for the frequency or likelyhood of these events happening - multihulls cost (as near as makes no difference) the same to insure (per dollar value) as monohulls.

Insurance companies base their premiums on statistics, not on opinion. If multihulls represented a greater risk, they would be charged higher premiums.

And this is getting off topic.

 

It is at this point that another form of logic, apparently missed, becomes the overriding point of the exercise. I call your attention to Post #1 of this thread. All of the words so shown there stating the original question of the thread (as seen below)

The clue was the Hornet's nest thing and now, apparently, we have arrived at the location as predicted. ;-)

 

yes, it certainly is.

Anyway, your "premium" claim doesn't really go to the core, does it (it was rhetorical, because it really doesn't).

The insurance is not based on risk of capsize vs. risk of sinking, thus your argument is utterly flawed. Now, if each capsize of a catamaran meant a total loss as is often the case with a monohull sunk, then you might have a point. Unfortunately it doesn't. Secondly, your argument fails to take into account how much the average multihull is insured for, as opposed to the average monohull.

And, once again, please read the first five words of the last paragraph in post number 53.

 

The point is that the argument is silly.

A blanket statement that monos sink and multis capsize is not worth consideration.

The statement "But a multihull seems to have a bigger risk at capsizing than a monohull has for sinking." has not been supported with fact.

Since monos sink for any number of reasons, while cruising multis only capsize in extreme conditions, I think the statement was intended to start yet another multi vs mono argument. If not, support the statement, don't come back with "What makes you think otherwise, I may ask?".

??? This makes no sense. What do I neglect to compare? There are ****** sailing both monos and multis. I won't guess if the percentage of ****** is higher on monos or multis.

Facts please. The last time I looked at those numbers (for British Columbia and the USA) that statement is false.

LOL .. of course the argument was ridiculous. Do you really think that more cruising multis have capsized than cruising monos have sunk? You make the statement, you back it up with numbers.

You are a piece of work. I said: "It is my *opinion* that you have to make a bigger error to capsize a multi than to sink a mono." How you get that I think that monos sink a lot from that is beyond me.

I have stated what is my opinion and what I think is fact. Where do you get that I'm "the defender of multihulls"? I started this thread in an effort to learn more about the relationship between waterline length and speed in multis. I don't think a case can be made for monos if your goal is sailing fast, but I am neither anti-mono or pro-multi. Multis and Monos each have their place. For instance, if the place is the sea bottom you will find more monos than multis

I don't have to back anything up, you made the statement "But a multihull seems to have a bigger risk at capsizing than a monohull has for sinking." It is you that have to back up your statement.

You started a mono vs multi argument in my thread. I don't appreciate it. Take your unsupported opinion and start your own thread. If you come up with a fact or two to support your statements fine, I might even enjoy the debate.

 

GOOD ONYA RHough.

Now lets get back to the TOPIC. (Which isn't monos vs multis).

 

Read post #53, last paragraph, five first words.

Read post #53, last paragraph, five first words.

Neither has any of the other nonsense. Read post #53, last paragraph, five first words.

It wasn't "designed" to start anything more than the two similar statements preceding it.
For further on that: Read post #53, last paragraph, five first words.

Hmm, when one pulls forth something like insurance costs, as to "Prove" that A doesn't capsize as often as B sinks, there's a whole slew of factors neglected. I already mentioned a couple. But the thing is, if you use insurance cost to make your argument in this case, you're reading statistics like the devil reads the bible (forgetting for now I'm an atheist).

Actually, it doesn't matter if it's false or not. The whole point of the motorcycle-analogy was that when comparing risk of A vs. risk of B, one cannot simply say that because most of the "incidents" of A is based on "Human error", the "real" risk is smaller, as was inferred by your argument.

Read post #53, last paragraph, five first words.

Hmm, perhaps because I see multihullers capsize a lot - from small to bigger, and certainly within the racing fraternity.

And for more on that, read post #53, last paragraph, five first words.

Actually, I claimed that that statement was just as nonsensical as the one preceding it. For more:
Read post #53, last paragraph, five first words.

Wow, buhu! Seriously, I sometimes find this funny. Some tosser (yes, I am one too) says something, but the moment one counters it, one are told to shut the **** up. Nice going.

Read post #53, last paragraph, five first words.

 

DB,

I'm under the impression that Randy H., as well as a few other posters, have seen this kind of discussion before and find that it, essentially, goes nowhere.

It's not my experience that Mr. Hough would be rude without purpose, so my take would be that he's simply asking you to let it go for the benefit of all who are following the thread.

That is not a F_ _ _ OFF kind of statement from what I know of the gentleman.

I'm asking... How about moving on to something more like the origins of the thread?

Regards,

Chris O

 

I AM letting it go. I have numerous times referred to post number 53, last paragraph, five first words. I cannot help if people continue to ignore that statement and think they're arguing with me, having to prove anything. My point was, and is, that one can make equally nonsensical statements, and when people argue the multihull-case (whether they admit it or not), they don't use proper argumentation. For all I care, people can prefer whatever they like.

So, hopefully for the last time: #53, last paragraph, five first words.

And yes, I'm outta this thread.

 

Okay, this proves you are not here to add to the topic.

The thread started to wander about post #50.

After your post #55 that contained "But a multihull seems to have a bigger risk at capsizing than a monohull has for sinking."

You refused to support your statement and came back with a smart assed reply. "What makes you think otherwise, I may ask?"

I'm not telling you to shut the **** up. I'm telling you that while others were poking fun at monos, you jumped in to stir the pot and make an argument out of it and I don't appreciate it.

I enjoy a good, senseless, mono vs multi debate as much as the next guy. Just not in my thread.

 

Sigh … Read post #53, last paragraph, five first words.