Characteristics of Offshore Yachts

[boom23]

Originally Posted by valhalla360

My point is proven by the comments in this thread that imply to try and cross oceans in a catamaran is equal to a death wish because they all flip and stay that way at the slightest breeze. Yet, I've read stories about how catamarans chasing the fleet, thought it was a bit rough but nothing to get excited about while the supposedly blue water mono's were falling over left and right. This isn't to say that mono's can't go to sea just that you need to get multiple view points because they all come with biases.

I agree...

My wife and I are currently in NZ, getting ready for Fiji. We crossed and sailed around the S. Pacific on our Lagoon 450, our first sailboat (after many powerboats). I have not crossed oceans on a monohull but I can tell you that on our catamaran we were almost too comfortable even at the roughest weather we encountered. At the same time, most monohull cruisers I talk to, say that they are tired of the boat leaning all the time especially during bad weather. I know though that one day I will own a monohull, as it is in my bucket list.

This is the start of our second season in S. Pacific. To my astonishment, I've seen all kind of boats that crossed the Pacific. Some were crewed by 70+ year old couples, some much less than 30ft, one with no navigation electronics (laptop computer got wet) except an iPhone. I am now convinced that careful planning and good seamanship are more important than a bluewater boat. If one has a boat that is maintained and manages the sails and steers the boat correctly he should survive any storm, during sailing seasons.

Anyway, I do not know if I am getting my point across. To rephrase, you can all sit there and argue until forever for the right boat. At the same time, some of you are actually out there enjoying our beautiful world with whatever boat they have.

Life is short... Enjoy it while you can.

Now, back to planning my next adventure!

Blog: Et Voila Adventures

[Steadman Uhlich]

Originally Posted by boom23

I agree...

My wife and I are currently in NZ, getting ready for Fiji. We crossed and sailed around the S. Pacific on our Lagoon 450, our first sailboat (after many powerboats). I have not crossed oceans on a monohull but I can tell you that on our catamaran we were almost too comfortable even at the roughest weather we encountered. At the same time, most monohull cruisers I talk to, say that they are tired of the boat leaning all the time especially during bad weather. I know though that one day I will own a monohull, as it is in my bucket list.

This is the start of our second season in S. Pacific. To my astonishment, I've seen all kind of boats that crossed the Pacific. Some were crewed by 70+ year old couples, some much less than 30ft, one with no navigation electronics (laptop computer got wet) except an iPhone. I am now convinced that careful planning and good seamanship are more important than a bluewater boat. If one has a boat that is maintained and manages the sails and steers the boat correctly he should survive any storm, during sailing seasons.

Anyway, I do not know if I am getting my point across. To rephrase, you can all sit there and argue until forever for the right boat. At the same time, some of you are actually out there enjoying our beautiful world with whatever boat they have.

Life is short... Enjoy it while you can.

Now, back to planning my next adventure!

Blog: Et Voila Adventures

I liked reading this post. Thanks for putting it in the thread.

[mstrebe]

Characteristics of offshore yachts is an excellent book that anyone considering an offshore boat should read. That said, most keelboats are made to its parameters these days. It's actually hard to find hulls with very serious violations.

Secondly, it takes both good seamanship and a seaworthy boat to safely cross an ocean, but both of those factors merely reduce risk, they don't eliminate it. Fools can be lucky in bathtubs, and professional sailors can die in a battleship. One-off anecdotes of success or failure mean nothing when you're talking about risk, they serve merely to reinforce incorrect cognitive biases for or against something. You can't prove anything with an anecdote.

There's no such thing as a perfectly safe boat in every storm, and no such thing as a sailor who can face down any typhoon every time in any boat.

What turns anecdotes into useful information is compiling a lot of them into statistics. Once is an accident. Twice is a trend. Ten times is a characteristic. The more information we compile about seaworthiness, the more seaworthy boats we can make.

In the Fastnet '79 race, many boats that lied ahull were capsized, but none that hove-to were. Because we're talking about hundreds of boats, that provides real statistics that mean something. It proves that regardless of type, keeping the bow (or stern) to the waves is vastly safer than letting the boat simply drift. A wave 1/3 the LWL of a boat can capsize it from the aft quarter, but a boat can survive waves longer than its LWL if its met bow on. That's a dramatic safety factor that requires constant seamanship during a storm--you're much safer if you tend your direction during a storm and don't just batten down and pray.

The new stability index (STIX)-based CE regulations in Europe are having a dramatic effect on manufacturers. My boat (which for me is a weekender) was build to have an All-Ocean rating--but only just barely. If you run the numbers, you can see that Beneteau modified the boat's design to be safer in order to achieve the A rating they wanted for the boat. So you've got a marketing factor ("All ocean rated") with real meaning in these CE regulations. I think it's going to save lives ultimately, as manufacturer's cannot simply self-certify a boat as being "blue water". It now has to mean something.

The Stability Index itself is based on insurance actuarial data and statistics from disasters like FastNET and Sydney-Hobart. It's not complete, but it is good solid statistical information about what makes a boat safe, compiled into numbers that boats can be built to. That's how disasters come to have future meaning that benefits all.

Finally, while the physics remain the same, our ability to model them with finite state analysis and computational fluid dynamics (CFD) make it possible to run simulations of hulls in storms thousands of times over to test permutations of ideas and effects of seemingly minor changes on stability and recovery. This is also vastly improving form stability of hulls and providing exact information about what is required of a keel to right a boat.

It was CFD modeling that proved that in fact a boat needn't avoid being beamy to return upright, because guess what? In a storm, there's ALWAYS another wave that will start the return roll. As long as the boat is more stable right-side up than upside down, it will return to right-side up.

Click on my boat and you'll see a boat decried as a floating hotel. It's all there, open interior plan, care taken with interior design, beamy.

Well, it's CE all ocean rated, it will roll back over within 3 minutes if it's turtled despite its beam, it'll float on either side with its companionway above water should it loose its keel, and its hull form has been tested in a CFD virtual storm thousands of times over with waves hitting from every direction.

And before you say that computer simulations are meaningless and statistics won't save anyone, please back your opinion up with something besides bloviation and anecdotes.

[Terra Nova]

Originally Posted by boom23

...I am now convinced that careful planning and good seamanship are more important than a bluewater boat. If one has a boat that is maintained and manages the sails and steers the boat correctly he should survive any storm, during sailing seasons...

Says the man with a catamaran.

"...during sailing seasons..." LOL

[Robin3]

Originally Posted by jwcolby54

And if your angle of vanishing stability is where the mast is in the water then a lot of wind (almost always accompanied by waves) will do exactly that, knocks you down and the "vanishing stability" takes over. The angle of vanishing stability is determined by ballast / depth and hull shape, no?

If you have passed the AVS then you most likely are headed totally tits up.
Whether you right again from bing upside down is down to wave action and luck but aided by any buoyancy in the upperorks that makes the tits up position unstable.


A lot of wind alone can knock a boat flat or nearly so at which point the wind has nothing left to lever on, the wind spills from any sails and the ballast takes over its job, righting the boat. A lot of factors influence the AVS, you can google to find books on it if you prefer to read rather than test the theory yourself

'Painting by Numbers' never made a newbie into a rival to Renoir or Van Gogh and 'Sailing by Numbers' doesn't guarantee safety afloat either but it could keep you firmly dry at home in an armchair whilst many others are out enjoying themselves even (or especially) if they stay out of the likes of Southern Ocean in Winter.

Oh and I have had the mast in the water a couple of times, not in my current boat ( a Beneteau, should I ever dare take that offshore after reading this thread and similar) but once in a little 1968 shoal draught 24 footer hit by a line squall thunderstorm with accompanying hail that had us don dive goggles and cookpans as hats and once in a 1970 IOR Half ton Cupper in a spinnaker broach ( skipper error, trying to avoid a drop and rehoist for a short race leg iwhen I got too close to the wind fast reaching under the kite in a F6-7, we survived but the kite didn't, leastwise not intact anyway and it retired from racing that day too.

[thomm225]

Originally Posted by Robin3

If you have passed the AVS then you most likely are headed totally tits up.
Whether you right again from bing upside down is down to wave action and luck but aided by any buoyancy in the upperorks that makes the tits up position unstable.

The Contessa 32 has an AVS of around 156 if I remember correctly. If it rolls over completely it's going to roll back up. Check the data. Luck has nothing to do with it.

CONTESSA 32 sailboat specifications and details on sailboatdata.com

The story of Alan Ker - Yachting World

An S&S 34 is another boat that's going to roll right back up even on a 360 roll:

S&S 34 sailboat specifications and details on sailboatdata.com

http://youngestround.blogspot.com/20...and-drama.html

[Whitebread117]

I would hope that ANY boat would right itself after a 360 degree roll. After all, 360 degrees from the starting point is in fact the starting point

You guys crack me up. To listen to some of you would make me believe that any boat with a broad beam and/or fin keel survives a gale by the grace of god alone.

[sailorboy1]

Originally Posted by Whitebread117

You guys crack me up.

Well The Book says

[TeddyDiver]

Originally Posted by mstrebe

It was CFD modeling that proved that in fact a boat needn't avoid being beamy to return upright, because guess what? In a storm, there's ALWAYS another wave that will start the return roll. As long as the boat is more stable right-side up than upside down, it will return to right-side up.

Wishfull thinking I'd say to pray for the next big wave
Rather stay upright or if that's not possible return upright without delay..

[Whitebread117]

Originally Posted by TeddyDiver

Wishfull thinking I'd say to pray for the next big wave
Rather stay upright or if that's not possible return upright without delay..

That's the funny part. These boats that will absolutely right themselves within seconds of a 180 capsize are also the ones that will heel 30 degrees in 15kts of wind. Upright is a very relative term

[thomm225]

Opinions are great, but if we check the facts..... well there isn't a whole lot else left to say.

Hunter 410:

HUNTER 410 sailboat specifications and details on sailboatdata.com

Beneteau 37:

http://sailboatdata.com/viewrecord.asp?class_id=6096

S&S 34:

S&S 34 sailboat specifications and details on sailboatdata.com

Swan 36:

http://sailboatdata.com/viewrecord.asp?class_id=1735

Contessa 32:

CONTESSA 32 sailboat specifications and details on sailboatdata.com


Now you can decided which boat you would want to singlehand sail on a voyage that would take you 500 miles offshore where you get caught in a bad storm.

Also, I haven't seen too many reports of rudders being lost on a Contessa or S&S. (or a Bristol!!)

[sailorboy1]

Originally Posted by thomm225

Opinions are great, but if we check the facts..... well there isn't a whole lot else left to say.

Hunter 410:

HUNTER 410 sailboat specifications and details on sailboatdata.com

Beneteau 37:

BENETEAU 37 sailboat specifications and details on sailboatdata.com

S&S 34:

S&S 34 sailboat specifications and details on sailboatdata.com

Contessa 32:

CONTESSA 32 sailboat specifications and details on sailboatdata.com


Now you can decided which boat you would want to singlehand sail on a voyage that would take you 500 miles offshore where you get caught in a bad storm.

Also, I haven't seen too many reports of rudders being lost on a Contessa or S&S. (or a Bristol!!)

The 410


WAAAAAAY before some old Bristol!

BTW - I noticed you ducked the question about how many of these boats you talk about you have spent time on out in bad weather.

[thomm225]

Originally Posted by sailorboy1

The 410


WAAAAAAY before some old Bristol!

BTW - I noticed you ducked the question about how many of these boats you talk about you have spent time on out in bad weather.

I don't need to spend time on them. I can read the data. Read it and weep! Btw, did I mention I paid $2,000 for my boat.

Hunter 410:

HUNTER 410 sailboat specifications and details on sailboatdata.com

Beneteau 37:

http://sailboatdata.com/viewrecord.asp?class_id=6096

S&S 34:

S&S 34 sailboat specifications and details on sailboatdata.com

Swan 36:

http://sailboatdata.com/viewrecord.asp?class_id=1735

Contessa 32:

CONTESSA 32 sailboat specifications and details on sailboatdata.com

Bristol 27:

http://sailboatdata.com/viewrecord.asp?class_id=521

[Robin3]

Originally Posted by thomm225

I don't need to spend time on them. I can read the data. Read it and weep! Btw, did I mention I paid $2,000 for my boat.

Hunter 410:

HUNTER 410 sailboat specifications and details on sailboatdata.com

Beneteau 37:

http://sailboatdata.com/viewrecord.asp?class_id=6096

S&S 34:

S&S 34 sailboat specifications and details on sailboatdata.com

Swan 36:

http://sailboatdata.com/viewrecord.asp?class_id=1735

Contessa 32:

CONTESSA 32 sailboat specifications and details on sailboatdata.com

Bristol 27:

BRISTOL 27 sailboat specifications and details on sailboatdata.com

Be careful the pages don't get wet as you battle your next storm.

[thomm225]

Originally Posted by Robin3

Be careful the pages don't get wet as you battle your next storm.

Wet is fine as long as I can make it back.

So your ballast is?

You and that other guy didn't read the book did you?

Did I mention I paid $2,000 for my boat? Check out the paint job. See attached.

OCEANIS 36 CC (BENETEAU) sailboat specifications and details on sailboatdata.com