Why do you guys like monohulls so much?

[Pelagic]

Just thinking out loud....
Is it possible that a new design, with great weight discipline ...
.... That takes the best of multihull features (beam) (weight)

.....and aplies that to a single hull wth a full wide rounded bow and barge/scow shape
Aerodynamic house and rig
Canting keel with foiling properties and planing foils of the new Vendee generation to give us the best of both?

Of course then the urinators on here would need to holster their hoses

[Old fella]

Originally Posted by Cliffhanger

These comments intrigues me. My gut feeling tells me that it is correct from everything I have heard, seen and experienced over the years. I think the knockdown and rolling chances are fairly hard to are argue with. But are there any statistics that back up the chances of a monohull sinking is the same as a catamaran flipping?

NO. It’s a product of an over active imagination. It’s just people tipically trying to justify owning what they own, so they make up rubbish about what other people have.

[Don C L]

As long as it's up on it's foils I guess, but that flat hull will sure slam if yer not on a lake, unlike the sleek multihull, no?
A cruising boat with canting keel and foils? Now that is some interesting thinking out loud.

[smj]

Originally Posted by wingssail

My gut feeling does not agree with yours. Yes, a knock down (whatever you define that as) on a monohull is much more common than a catamarn flipping. The consequences, however, are worlds apart. Knock down is NOTHING! It happens, Then your boat stands up again and it's over. You pick up the apples and oranges off your cabin sole, and you go on your way.

You flip on a catamaran and it ruins you whole day.

Getting rolled 360 degrees on a monohull is infinitesimally rare, considering how many are out there cruising the world. Catamarans getting upside down is fairly common, I think, according to the news we all see. But if you've got any statistics to back that up SMJ, then please share them with us.

Monohulls sinking? OK that happens, rarely caused by a 360 roll.

Your description of a knock down is what happens when you heel 35 degrees, not get knocked down.....though it does give a rosy outlook!
This is something written by an ex forum member, and pretty much mimics what insurance agents have told me.


" Before I retired from the NTSB I had the opportunity 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."

[fxykty]

Originally Posted by wingssail

My gut feeling does not agree with yours. Yes, a knock down (whatever you define that as) on a monohull is much more common than a catamarn flipping. The consequences, however, are worlds apart. Knock down is NOTHING! It happens, Then your boat stands up again and it's over. You pick up the apples and oranges off your cabin sole, and you go on your way.

You flip on a catamaran and it ruins you whole day.

Getting rolled 360 degrees on a monohull is infinitesimally rare, considering how many are out there cruising the world. Catamarans getting upside down is fairly common, I think, according to the news we all see. But if you've got any statistics to back that up SMJ, then please share them with us.

Monohulls sinking? OK that happens, rarely caused by a 360 roll.

I’m not sure about the “catamarans getting upside down is fairly common” comment, if we’re talking about cruising catamarans and not catamarans that are not racing.

Stats are very hard to compile, so as a proxy I suggest we look at insurance rates. Asking my broker here in New Zealand, he says that the rates are roughly the same where there is equivalent experience in the type of boat. Where people are new to cats their blue water policy will be slightly more expensive than if they were newbie monohull cruisers in an equivalent value boat, and the rate comes down as they gain insured experience.

That indicates to me that the flipping of cruising catamarans is not significantly higher than the sinking of cruising monohulls. The latter are much less photogenic, though.

[Old fella]

Originally Posted by Jim Cate

That is impressive if inexplicable. How do you reckon it was possible?

In our similarly sized relatively light boat (but with >44 feet of waterline) we've had a couple of surfs in the mid 15s and some sustained 11s... also with plain sails. It is a mystery to me how the subject boat could be so fast.

Jim

Jim, I once touched 8 knots in my little h28, I quickly looked over the side to see if I was sitting on top of some poor whale, but no. It must have been the once in my life I had the sails set properly. Maybe he was sitting on top of a whale.

[wingssail]

Thnk you SMJ for digging that up, but it doesn't really substantiate your contention about rates of roll overs vs flipping.

You source is giving his (her) interpretation with no numbers, and even then you have to spin it to get to the conclusoin you presented. See my comments in red.

Originally Posted by smj

Your description of a knock down is what happens when you heel 35 degrees, not get knocked down.....though it does give a rosy outlook!
This is something written by an ex forum member, and pretty much mimics what insurance agents have told me.


" Before I retired from the NTSB I had the opportunity 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.

He refers to "loss" not mentioniong if they hit a reef, or rolled over.

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.
Again he talks about declining numbers, and increasing numbers, but gives no relative numbers.

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.

The above pargraph tells us nothing about roll overs or flipping or sinking

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."

Yes, I'd agree with that, considering we're talking about all sorts of injuries and deaths, not sinkings, roll overs, or flipping cats

Please, if you want to validate your claim you'll need to do better than that, otherwise we're left with gut feelings.

[wingssail]

Originally Posted by smj

Your description of a knock down is what happens when you heel 35 degrees, not get knocked down.....though it does give a rosy outlook!...

35 degrees is not a knock down unless it happens so suddenly that it scares the people on board, then when the get back to the dock they speak of "we got knocked down"

A knock down, in my defination, is knocked flat or nearly flat suddenly and the boat loses control and rounds up into the weind, sails flapping and people rather startled.

The consequences are just as I stated.

[newhaul]

Originally Posted by Old fella

Jim, I once touched 8 knots in my little h28, I quickly looked over the side to see if I was sitting on top of some poor whale, but no. It must have been the once in my life I had the sails set properly. Maybe he was sitting on top of a whale.

Actually sailing west from the Seattle ship canal outer marker toward the north end of braindead Island. With 25 to 30 sustained out of the north in mid October 6 years ago on the slack tide.

[malbert73]

I’m perfectly ok to believe that mono sinking and catamaran flipping is same risk (even though this may not control for sheer higher number of older monos out there- and age must certainly correlate to sinking risk so maybe it’s not equal?)
So, you have to decide what terrifies you more. For me fire is #1 (same in both boats) closely followed by inverting a cat. I cruise with young kids and the thought of trying find them in a sudden squall capsize is chilling to me however rare the risk could be. Sinking is really not as scary to me since I currently coastal cruise. And sinking rarely happens instantly as a cat capsize would be so there is time to get PFDs, EPIRB etc. I like well performing boats so I believe in that category capsize risk goes up quite a bit. And I’ve been caught in a couple of sudden line squalls in an otherwise benign looking rain squall and only got heeled over and rounded up.

So pick your (extremely rare) poison.

[smj]

Originally Posted by wingssail

Thnk you SMJ for digging that up, but it doesn't really substantiate your contention about rates of roll overs vs flipping.

You source is giving his (her) interpretation with no numbers, and even then you have to spin it to get to the conclusoin you presented. See my comments in red.



Please, if you want to validate your claim you'll need to do better than that, otherwise we're left with gut feelings.

I’m sure it’s impossible to get all the facts but let’s take the Queens Birthday storm as an example. Monohulls rolled 360, pitch poled, lost rigs and serious injuries......while the catamarans didn’t flip.

http://www.multihulldynamics.com/new...p?articleID=11

Real life example with both types of boats in the same conditions. Now you come across an example where multiple catamarans flipped and no monohulls rolled.
I’ll be waiting......

[smj]

Originally Posted by wingssail

35 degrees is not a knock down unless it happens so suddenly that it scares the people on board, then when the get back to the dock they speak of "we got knocked down"



A knock down, in my defination, is knocked flat or nearly flat suddenly and the boat loses control and rounds up into the weind, sails flapping and people rather startled.



The consequences are just as I stated.

A knock down is flat, 90 degrees with sails in the water. Everything that wasn’t tied down is thrown around including humans, unless of course your Spider-Man. [emoji23][emoji23]

[Old fella]

Originally Posted by newhaul

Actually sailing west from the Seattle ship canal outer marker toward the north end of braindead Island. With 25 to 30 sustained out of the north in mid October 6 years ago on the slack tide.

Sorry for doubting you mate, I’m just jealous. Maybe there is hope for me to whip past some of these fast cats, mind you, I do now, but generally they are on anchor. You have a good day bud, cheers Brian.

[newhaul]

Originally Posted by Old fella

Sorry for doubting you mate, I’m just jealous. Maybe there is hope for me to whip past some of these fast cats, mind you, I do now, but generally they are on anchor. You have a good day bud, cheers Brian.

Hey surprised the heck out of me to .

[wingssail]

Originally Posted by malbert73

... And I’ve been caught in a couple of sudden line squalls in an otherwise benign looking rain squall and only got heeled over and rounded up...

According to the fear mongers, that is a "knock down", serious enough write articles about and give seminars to cruising wannabees for the next two years, feeding the nightmares of thousands of shivering souls who simply want it to be terrifying so they can tell their moms and families around the Thanksgiving table and see the horrified looks of their siblings who then say, "You're really going to do that?"