Following Seas and Cockpit Height

[messias]

Hello everyone,

This is really (unfortunately not surprisingly) becoming a nonsense discussion as arguments tend to be more and more based on personal opinions rather than on real facts, straying away from RED HERRING´s question.
I never owned anything larger than 20ft (and currently boatless) but I have sailed both monos and cats... no hate towards any of them (as long as I can sail, everything is fine)... but I do agree with "OceanSeaSpray" regarding the FACT that all boat designs have limitations. Every boat is thought, designed and built to a specific purpose. anything straying away from that intended purpose will inevitably be taking it beyond its possible capabilities. From that point on you will be taking your chances (if you do get away with it, it's a mix of seamanship and luck...and no one will know for sure) With this, I think everyone HAS to agree with.

I would prefer to sail a cat, if I would be cruising the tropics and expecting to spend a lot of time socializing at anchor, with the wife and kids and neighboring boats...

I would prefer to be in a steel/alluminium monohull if I was hoping to cruise the tropics AND those higher latitudes where the vast majority of boats will never go... (and where I -one day- hope I will be able to go)

How many multihulls owners choose to cruise permanently on 40º/50º/60º South ? Not many (if any) and why would that be? Maybe because they were not built for that and would be pretty darn foolish to test your luck that far for that long.

How many steel monohulls with cramped and "uncomfortable" interiors and with perspex domes cruise their entire time in the tropics (comfortably)? Not many (if any)? and why would that be? Maybe because they would be the most perfect oven in the world.


Food for thought, beyond biased opinions. There is a limit to any boat. No engineer brain is needed to come to this conclusion. Pure comon sense (it´s becoming more and more a rare asset). There is a main purpose behind every design.
Please leave all of your hates in the drawer.

Now... in my own opinion (please note that and feel free to disagree. I respect it):
A multi will always be better than a mono... in comfort.
A mono will always be better than a multi... in (really nasty) heavy weather.

[messias]

From the below vessels, which would be your choice for a month on South Georgia and the South Sandwich Islands? and in Anvers island?
And which would be your choice for a month in Moorea?

Make your unbiased choice and you´ll have the ultimate answer on "the better boat for the job"





https://www.google.cz/url?sa=i&rct=j...55356863325860

https://www.google.cz/url?sa=i&rct=j...55356601111884

[clownfishsydney]

If you are not a catamaran owner, why would you even respond to this post?

[messias]

Originally Posted by clownfishsydney

If you are not a catamaran owner, why would you even respond to this post?

Humm.. sorry. I though we were addressing sailboats here...but I might be wrong.
Well... are catamaran owners the only ones allowed to give some input on boat design? Does ownership come with a guarantee of physics knowledge?

This is exactly the kind of comment that (quite frankly) seeds disaster.

geee... i am out of here. Have fun.
I am sorry for questioning anything. and yes... for sure your boat (or any other boat) will handle anything anywhere.

[barnakiel]

But we are talking pussycat boarding waves here? Ones that will wait for the boat to lift her ass?

Guys and girls: a proper one will not. Will break exactly when it is touching the stern, poop any cockpit and break anything that is not designed to take the huge load.

Not a reason to bash charter cats. They are designed to sail in the lee of islands and they do it very well. The huge doors slide, let plenty of light in and open the main living space of a cat.

There are cats with smaller, stronger, non-sliding bridgedeck doors too. If you want to sail where the waves are bad, get one.

http://www.cruisersforum.com/forums/...1&d=1259192565

So now that you have those strong doors, what next will give?

;-)

b.

[rabbi]

Why would anyone with no experience on the subject (following seas on a cat) feel he has any reason to answer?
To repeat what he heard or read somewhere, to spread unsupported facts?

I would never participate on a discussion about a death roll on a mono. Why should I? I have nothing to add to this discussion. I would also not post something like "Haha, thats no problem on a cat". I just don't care!
I have nothing against monos, I just don't sail one and never will. So why should I start a fight in an area where I have nothing meaningful to say?


On the other hand there seem to be more and more mono guys coming into the multihull forum to tell us how miserable we are. That we are on the edge of desaster, that our families will dron after the sliding door has exploded, that we will flip in a puff, and motor even at anchor. Most of these folks have exactly nothing substantial to add to any discussion over here.
But they drag a good portion of all multi threads into the mono vs. multi debate. A debate that seems to stay alive only in a monohuller head.

Look at the first reactions: Sliding glass doors are a huge problem, they will explode! Unsupported nonsense.

Agreed, these doors will never survive a green wall of water. BTW: the tires on a Honda Civic will never survive 300Mph.
I have never seen or heard of a cat that had the door explode by a following green wall of water. Just as I have not heard of a standard Honda Civic doing 300Mph.


Sliding glass doors are sometimes a PITA: these damn rollers that keep them sliding are of poor quality, corrode fast and are hard to source at least where I live. But they don't explode.

[rabbi]

Originally Posted by barnakiel

Not a reason to bash charter cats. They are designed to sail in the lee of islands and they do it very well.

Jesus. Why has nobody ever told me that. I will never again leave the lee of the island.
So which one is the lee side of Sicily?

[messias]

Originally Posted by rabbi

Why would anyone with no experience on the subject (following seas on a cat) feel he has any reason to answer?

Hello Rabbi,
That´s an easy one...

Because the thread was about the possible relation of following seas with cockpit height. That is not exclusive to cats. And believe it or not, I am interested in boats... would they be either cats or monos. I truly believe this is a common interest for any person interested in boats and cruising, therefore, that line of thinking that if someone who does not own a cat is automatically left without any valuable input to give here and that they have no right to talk about the possible conditions encountered at sea is, in my opinion, well... sad.

And (also) believe it or not, I come to CF to read, learn and contribute with what I can across all sub-forums... would they be cats, monos or cooking. But I guess that´s not the case for some of CF´s users. Again... sad. Not only sad, but it only takes us apart from each other further and further.

Would you not comment on a question made in the monohull section?
Do you read them at all?

I believe you do, so what´s the issue here?
Like in any other forum, it is up to the original "poster" to filter out what is the value of the answers given.

From what I know (although I am no Naval architect), hull design plays one of the biggest roles in a following seas situation. It is pure physics, so the exact same principles apply to anything afloat. Cats, monos and 26ft lost containers included... so, again, why would a "monohull person" not be "allowed" to comment on that? In fact, why would a boatless person be restricted as well? They have nothing valid to add? Really?

[estarzinger]

For the OP, personally I would be more interested in increasing water clearance to minimize wave slam on the underside of the boat. And I would also personally want to minimize total height to reduce aero drag. And there is an obvious trade off and sweet spot between those two objectives.

As to pooping. I can make three comments.

#1 There is a particular operator error that is much more likely to cause it. I personally have made that error (and hopefully learned from it). We were in big waves and the wind was building and we wanted to switch down from the #3 to the storm jib. Our plan was to roll up the jib and hoist the storm jib. There was enough wind to keep the boat steering under bare poles as we were doing that. BUT when we rolled up the jib the boat decelerated, just as a big breaking wave rolled up the stern, and right over the cockpit. If we had kept up speed that wave would not have broken over us, but with the sudden deceleration it did. Hit the cockpit pretty hard. What we should have done is hoist the storm jib first and then roll up the jib, but at the time it did not seem sensible to be adding sail area. (note: this was on a 55' custom M&M cat)

and

#2 There are just conditions when almost any boat of almost any design with almost any skipper can get pooped. These sort of conditions are quite rare. But they do happen. Take a look at video of the 1998 sydney to hobart storm if you want to see what it looks like. I personally would not have been real happy to be out in that weather with a big light weight glass sliding door . . . but there are also a lot of other things that would have made me uncomfortable in that storm. Big serious breaking wave weather is just really really harsh and can break a lot of stuff that normally is just fine. When picking and outfitting a boat you just have to ask what sort of conditions are you going to prepare for.

I will note again those sorts of conditions are rare - and often a cruiser can sit them out in a nice safe harbor - but sometimes even the tropical cruiser does get hit by them when doing long passages (see queens birthday storm for example)

and

#3 Somewhat related to #1, but a broader point - operator experience and skill can mitigate ALOT of boat/design vulnerabilities. And operator inexperience can dramatically increase risk. And the more finely tuned the vessel the more these things are true. In sydney to hobart sort of conditions there are three factors:

(a) there is just a certain amount of luck involved. If you get hit by that certain wave in that certain wave, it is going to destroy you almost no matter your skill and almost no matter your vessel design (we are talking recreational sail boats here).

(b) there are certain design elements that increase risk. I would say that the single biggest is a lack of tracking in big waves, and (to make a generalization) multihulls tend to track/steer better than monos (which when heeled on the face of a wave often change their steering balance and want to drive around). But I have to comment that down the 'added risk' list a ways are big pieces of glass - both from wave pressure but also from gear strikes (see rainmaker). Most commercial classification rules have long sections about size and engineering of big glass pieces. These can in fact be made really really strong (Dashew does) but that tends to be really really heavy and it is not often done of multihulls.

(c) Operator skill and experience can mitigate ALOT of risk. And operator inexperience can increase risk dramatically. And this factor (generally) increases the more highly strung the vessel. Highly experienced and skilled guys might not have flipped that Chris White 46 (?)

Boats are trade-offs. If you build the 'any seas, any seasons, any storm' boat then you will have made a lot of design decisions that will make the boat a bit less attractive in typical conditions. So, it is a tricky dance to make the right trade-offs for you. And that is one reason this is so hard for inexperienced people because (whether they know it or not) they just don't know yet what are the right trade-offs for them.

[rabbi]

Originally Posted by messias

Would you not comment on a question made in the monohull section?
Do you read them at all?

I believe you do, so what´s the issue here?

I rarely read mono-specific questions, and almost never answer. Simply because I think that I know next to nothing about what makes a mono do what it does.

Originally Posted by messias

From what I know (although I am no Naval architect), hull design plays one of the biggest roles in a following seas situation. It is pure physics, so the exact same principles apply to anything afloat. Cats, monos and 26ft lost containers included... so, again, why would a "monohull person" not be "allowed" to comment on that? In fact, why would a boatless person be restricted as well? They have nothing valid to add? Really?

The OP decided to put the question in the multihull forum, with two cats as examples. So I think he was trying to understand how cats behave in following seas.
Not how a mono or a container behaves.



If someone posted this in the monohull section with two monos (or containers) as examples I would not feel entitled to give answer.
I'm a cat sailor with not much experience in monos. So what could I contribute to that discussion? Nothing, because it would just be 2nd hand blabla and my own unfounded conclusions derived from that.



Look at the comments by most monos in his thread. Just 2nd hand blabla and unfounded conclusions given as facts.

[Liam Wald]

A forum is not a support group.
Although many people only want to talk with those who drink their cool-aid and completely agree with them, that is not how open forum type discussions work.
Forums are about sharing opinions and being open to respectfully considering opposing points of view.

[StuM]

Originally Posted by rabbi

Jesus. Why has nobody ever told me that. I will never again leave the lee of the island.
So which one is the lee side of Sicily?

Guess I'll have to stop crossing the Coral Sea now!
Damn, there go my trips to Qld and the GBR.

[monte]

Great post by Evans above. I think the op is on the right track with catanas or the L470. Clearance is a good thing, but note that a lot of cats with very low clearance have made difficult passages safely as well, such as heavenly twins and prouts. All circumnavigating and some cases around Cape Horn. While never having been pooped or close to it on our L380 or L400 (we have had a splash in the cockpit on occasion) there is always the possibility from a disorganised following sea. That said we've never felt the need to close the sliding door on passage except for near horizontal rain from a squall that would wet the floor for a few feet inside. In the event that we were to be pooped with the door closed, I would expect it to be strong enough to cope with 1m high ingress. In the event that it failed I would expect the ingress to be dispatched fairly quickly by the bridgedeck drains and bilge pumps. It's always good to consider 'what if' scenarios like this and plan accordingly. Being pooped, along with MOB, hitting a whale, etc. is a 'what if' that hopefully we will never have to deal with.

[ZULU40]

Originally Posted by OceanSeaSpray

Failings or "specialisation"? We used to design boats for "all weather, all conditions". This is clearly not so true any more.

Racers like you showed above get away with open transoms because they ship water from forward, never aft, and it is the quickest way to clear it - together with a few crew members if possible.
A boat doesn't need to be particularly extreme at all never to ship one over the stern however. It mainly needs to be easily driven and capable to accelerate.

my point also related to cruisers, and they arent hard to find

[44'cruisingcat]

Originally Posted by rabbi

Why would anyone with no experience on the subject (following seas on a cat) feel he has any reason to answer?
To repeat what he heard or read somewhere, to spread unsupported facts?

Yep. That's exactly why they're here.