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Old 01-08-2012, 10:58   #76
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Re: whats the safest kind of hull?

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And where are those facts? Have a link?
Nope but it was brought up by Sandy D in another one of these mono vs multi threads. I will see if I can find it.
Before we bought our first cat 20 years ago I talked to Lloyds of London and they told me I would get a better rate with the cat than the mono because of the stats but I'm sure a lot has changed since then.
The way I read the old post by Sandy D there really wasn't much of a difference between the multi and mono so whatever choice you make should be good.
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Old 01-08-2012, 10:59   #77
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Re: whats the safest kind of hull?

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(...) Are there any monos that dont sink when one hull gets filled with water? Any Monos that can keep up with a comparable multi to simply avoid weather?

(...)
Many Etaps, Sadlers, e.g., do not sink when holed and waterlogged. Amels have watertight bulkheads. Etc.. Unfortunately, many very recent, very popular designs do not even sport a dam between the rudder pipe and the rest of the hull.

Very few multis or monos can sail fast enough to dodge some (not all) weather systems in some situations.

In cruising aspect, 'dodging the weather' is exercised best by being tied to a safe dock in a safe marina. When heading offshore, the cruising boat should be built to withstand the kind of weather that can be encountered there.

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Old 01-08-2012, 11:07   #78
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Re: whats the safest kind of hull?

Let me try another tack, somebody please find the OP a safe world cruising multi for 20k.

Now, I personally know some folks that got a nearly complete homebuilt project 50' cat for free, it just had to be moved but even that one cost them 40k to equip. (+5k to move)
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Old 01-08-2012, 11:13   #79
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Re: whats the safest kind of hull?

Here's the NTSB report.


Escape hatches are required by law in the CE. Thats why you see them on many cats. Their desireability is open to question.

Before I retired from the NTSB I had the oportunity to study the complete Coast Guard database of boating accidents and Summary
Data of proprietary actuarial information from sources within the Lloyds' Groups, with a focus on vessels with accomodations including permanent berths, head(s) and galley. I tried to exclude beach cats and tris, and daysailers by excluding boats under 24 feet. The data was not user-friendly and required a lot of external correlation because many vessels were incorrectly classified. That ultimately prevented releasing any conclusions because GI+MGI=GO (garbage in plus more garbage in still equals garbage out.) This was also a problem with the older NTSB databases that included pre-digital-age reporting. However, I discovered in the process that there were few differences between monohul and multihull rates of occurrence. That's easy to understand; human error trumps mechanical failure and design deficiency evermore. Here are some of the facts that did become apparent: Vessels designed for racing and record attempts break. Vessels built for cruising don't break. People who race drive themselves and their vessels to the limit. [please forgive the pun] Cruisers drive their homes to the next nice place.
The rates of actual vessel loss (outside of competition) remained the same for monohulls and multihulls, over many years, with catamarans emerging slightly ahead of other vessels in the last years of available data. Reports of large numbers of catamaran roll-overs are probably anecdotal as accident statistics reveal a (slight) decline, with a slight increase in sinkings among monohulls. There was a lot of confusion in the data between catamarans and trimarans, which I can only suggest an interpretation for:

Vessels purpose built for competition are not recorded as such. Each accident had to be researched individually. Many were not insured, meaning that Insurance data would not take them into account. In fact, Many sinkings of monohulls were extremely difficult to document because they were never widely reported. This is changing as news media is becoming more interested, especially in colorful visuals.

A very small percentage of trimarans are sold for cruising, as a very small percentage of catamarans are sold for racing. The best correlation between racing and competition vessels was a ratio of lwl to mast height.

Where I was able to distinguish between cruising and competition vessels, I found that the rate of personal injuries and single fatalities was higher among monohulls. That should merit further study because those injuries appeared to occur in better weather conditions, not in worse. These accidents included cabin injuries, man-overboards, and deck injuries such as inadvertant jibes.

My conclusions were impaired by the quality of data, and my proposal of a National Transportation Safety Board Special Study was properly overshadowed by more important issues. But there is enough factual data to prove that cruising multihulls are no more, and possible less dangerous than cruising monohulls in all reported conditions of weather, traffic, and human frailty, regardless of location.

Note: this was 12 years ago.
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Old 01-08-2012, 11:15   #80
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Re: whats the safest kind of hull?

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Lotsa great opinions here but no facts. If you want facts you go to the insurance companies and their stats show the multi just slightly more seaworthy than a mono. The surprising stat is they show you have many times the risk of dying on a mono as compared to a multi. Must be the sinking vs. the upside down and floating thing.
Re: opinions vs. facts: can you share any link to the info you quote?

I have not seen such data before, maybe I was looking in all the wrong places. ;-)

THX in advance,
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Old 01-08-2012, 13:02   #81
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Re: whats the safest kind of hull?

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Here's the NTSB report.

...
Where I was able to distinguish between cruising and competition vessels, I found that the rate of personal injuries and single fatalities was higher among monohulls. That should merit further study because those injuries appeared to occur in better weather conditions, not in worse. These accidents included cabin injuries, man-overboards, and deck injuries such as inadvertant jibes.
...
smj
Interesting summaries. In the paragraph above, is your conclusion then based on cruising only vessels?
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Old 01-08-2012, 13:08   #82
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Re: whats the safest kind of hull?

Thank you to those who spent a little time writing a basic description for Alize.
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Old 01-08-2012, 13:43   #83
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Re: whats the safest kind of hull?

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smj
Interesting summaries. In the paragraph above, is your conclusion then based on cruising only vessels?
The study wasn't done by me but from what I can read he basis it on cruising vessels.
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Old 01-08-2012, 14:10   #84
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Re: whats the safest kind of hull?

Alize, You asked for advice on the safest hull and most responders answered as to their own opinion of what is best. Of course it depends on where you intend to sail and your budget... and you asked for all world. So my answer to you is to look at what those sailers who routinely sail in the worst possible conditions.... Like the North sea and anywhere off the coast of the UK, France and Northern Europe. What do they sail? Here's What I see around this area is an abundance of Hallberg Rassys, And to a much lesser extent but still very able Oysters and Amels for the serious cruisers who can afford a high quality yacht. I recently slept through a Force 8 in the English channel without a worry onboard our Oyster while the crew handled everything. I assure you, This wouldn't have been the same on our Previous boat.... A Hunter 450. I hope this helps.
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Old 01-08-2012, 15:50   #85
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Re: whats the safest kind of hull?

all yours advices helps me to put some info together... thanx a lot! to all of you !!!
i already know a i want a fiberglas monohull us i cant finance a catamaran! i think somethink like formosa32 -42 will suit me the best.
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Old 01-08-2012, 17:24   #86
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Re: whats the safest kind of hull?

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However, I discovered in the process that there were few differences between monohul and multihull rates of occurrence. That's easy to understand; human error trumps mechanical failure and design deficiency evermore.
Note: this was 12 years ago.
That has not changed.

I am a multi person.

If it makes a diff....

I did not see the post about 20k. Did I miss it?
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Old 01-08-2012, 18:07   #87
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Re: whats the safest kind of hull?

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I did not see the post about 20k. Did I miss it?
The OP cross-posted in a couple threads, sorry I got them confused: what is the best building material sor sailing boat?
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Old 01-08-2012, 18:10   #88
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Re: whats the safest kind of hull?

In the context of the OP's budget, a full keel mono may be good advice, but in the context of what's safest, it's striking that no-one has mentioned a quite different option favoured by (and some would say proven ... I would say, not disproved) a number of those who spend much of their time in the Southern Ocean or Antarctica.

Essentially a low-profile, strongly built metal canoe-body monohull with a ballasted keel, retractable inside that canoe body.

Ultimate stability is a static concept, which does not necessarily illuminate the dynamics of a small vessel on a big wave face when that wave breaks.

From the OP's chosen handle, and word usage, I wonder if he or she is French? The insight about dynamic response was pioneered by French designers and expedition sailors, who were (and remain) very prominent in these waters.

The analysis of the force vectors is persuasive to those blessed with an enquiring mind.

For some reason in the English speaking world the concept of retracting a ballasted keel in survival conditions remains abhorrent.

Yet I have not found any doubter who can point to an instance where this tactic (in this cadre of highly knowledgeable sailors, sailing in regions where encounters with large waves are eventually inevitable#) has resulted in inversion.

# unlike in hurricane latitudes, where the problem is seasonal.

Recently oceanographers have had to admit they were wrong about the prevalence of seas over say 20m, in the face of evidence from satellite programs, notably the late lamented QuikSCAT.
These waves are much more common than their theories had predicted, and most of these waves, it turns out, occur in the Southern Ocean.
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Old 01-08-2012, 22:43   #89
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Re: whats the safest kind of hull?

There has not been much said about hull shape, particularly with respect to following seas. I'm a bit new to all this but I thought a broad stern (looks pretty OK on the right shape) was not so good for large following seas?
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Old 02-08-2012, 02:20   #90
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Re: whats the safest kind of hull?

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There has not been much said about hull shape, particularly with respect to following seas. I'm a bit new to all this but I thought a broad stern (looks pretty OK on the right shape) was not so good for large following seas?
I think it depends on a lot of things. I had a nightmare trip down in the Southern Ocean once on a 52' steel yacht with a wide bum and a small rudder (and a long keel - quite traditional underbody).
There were six of us onboard and I was the only one who could navigate, and the satnav was playing silly buggers, and one by one the other members of the crew either succumbed to terminal seasickness or found themselves chronically unable to steer within 30 degrees of our course, which was a broad reach.

We had to scrape past Bristow Rocks (notorious for ripping the guts out of sailing ships) in order to have any prospect of laying Port Ross on Auckland Islands, otherwise we were likely (in a building westerly) to end up having to run off for several days towing warps, and maybe take a week to get back.

And so for about the last six hours I'm left in charge, trying to navigate with the sodden chart on my knee while steering this recalcitrant pig with the other hand. The only surviving crewmember, his face waxy pale, would hover sporadically in the companionway peering up at me like Banquo's ghost, intoning "Beware the Bristow Rocks" in an unhelpfully lugubrious and unsettling tone.

I always feel a certain degree of impish delight when I hear people making unqualified blanket assertions about the merits of full keels and protected rudders, and how easy they make it to steer a boat.

Having said that, the more extreme IOR boats of that era (early 80s) had tiny wee bums, and despite big deep rudders were equally nightmarish going downwind in a breeze or worse.

On the other hand, a very modern, wedge shaped boat, with almost no rocker, waterline beam nearly the same as beam on deck, and really deep, efficient rudders, situated and splayed out towards the corners (one of which will be ideally placed, and biting deep, when the boat is trying to broach), can be a delight to steer in big stuff downwind provided the crew are alert and competent. They can even be left to the tender mercies of a really fancy autopilot, and in single handed long distance racing, they generally are ...

even in what most cruisers would consider borderline conditions, especially for the amount of sail they're carrying.

However those rudders are very vulnerable because there's nothing ahead of them to take impacts. A cruising boat with twin rudders should (IMHO) have transom mounted, kick-up units, (or at least carry a spare or two, which can be built into the joinery, even used as doors - the pintles come in dead handy for this.)

Neither of these answers helps much when you're trying to assess a Beneteau, Jeanneau or Hunter.
But I hope it does suggest that the question (like pretty much all questions in a thread like this) has no simple answers.
If there's any remotely useful generalisation I can think to offer, it's that any boat which prioritises comfort (and volume of accomodation) is likely to be a handful in these conditions.
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