Following Seas and Cockpit Height

[dagranger]

Never owned a Cat but have sailed against them in Races off So Cal. Was witness to Imi Loa about 43 ft. cat being turtle and needed rescue for the crew. However the boat had nothing to do with capsize..according to owner Vic Sterns they were carrying too much sail and good strong force of wind caught them as they were on rise of swell and caught them under the hull, over..with all that said the boat was recovered and reoutfitted and still sailing in races all over So Cal..several trans pacs...winds at start were 25 to 30 and we had 45 across the deck most of the time not a good day to go racing which after 2 hours was called off..I don't know about all cats being built but if the build is good they will go anywhere at anytime and get their quicker with a whole lot more room..anyone thinking otherwise is just no willing to look at reality..Good Luck Don Friday Hrbor whitney series san nicolas island race 1974

[duefocena]

Originally Posted by reed1v

An 18 foot breaking sea would have more force than a locomotive. Water is like that. Extremely dense, heavy, and when moving there is not much on earth that can withstand it. Which is why a lot of heavy concrete bulkheads get torn apart during storms. Naval ships have lost bows due to wave action

Heavy concrete bulkheads after repeated battering and the fact that they are immovable. Naval ships losing bows? How often was that and the surface area is huge.
OP was asking for information and I thought that first hand was appropriate. And your experience or knowledge of others in a cat with breaking seas is? Maybe responses that help the OP would be favorable to " if big sliding windows are your thing".

[duefocena]

Originally Posted by morven55

Cat People seem to be easily irritated...not to mention defensive.

And a mono huller making uninformed observations is irritating. But the snarky poster not benefitting the OP or even commenting on the subject is of help to who? I look at this forum as a way to share knowledge. It has helped me and I hope to reciprocate. All boats are great in some way.

[Sailing55]

Originally Posted by duefocena

And a mono huller making uninformed observations is irritating. But the snarky poster not benefitting the OP or even commenting on the subject is of help to who? I look at this forum as a way to share knowledge. It has helped me and I hope to reciprocate. All boats are great in some way.

Irritating? Many things are irritating, including snarky comments...but why take the bait?

I was, actually, trying to lighten things up a bit. But you gotta admit, some Cat People are quite defensive, and easily baited.

Disclaimer: I have no negative opinions regarding cats or large sliding doors on oceangoing vessels.

[44'cruisingcat]

Originally Posted by morven55

Cat People seem to be easily irritated...not to mention defensive.

Yeah it does get irritating to have one's real-life experience ignored, while ignorant opinion rules.

[Sailing55]

Originally Posted by duefocena

And a mono huller making uninformed observations is irritating. But the snarky poster not benefitting the OP or even commenting on the subject is of help to who? I look at this forum as a way to share knowledge. It has helped me and I hope to reciprocate. All boats are great in some way.

And yes, all boats are great in some way. To each his own, and it is in poor taste to bash someones boat for any reason. Agreed 100%

[Sailing55]

Originally Posted by 44'cruisingcat

Yeah it does get irritating to have one's real-life experience ignored, while ignorant opinion rules.

At some point one just has to accept that the world is full of experts...and for some reason life afloat seems to attract experts in disproportionate numbers.

I am not familiar with cats, but they certainly seem to be the subject of a lot of controversy.

Don't let it get to you...look at it this way: the people that do listen to you are obviously of higher intelligence!

[duefocena]

Originally Posted by Liam Wald

Honestly, I was just commenting on "sliding glass doors" on boats.
I have nothing at all against multi-hulls. I just don't think that big patio style sliding glass doors are very good on sea going boats whether mono-hull or multi-hull.

What came as a really big surprise to me is the intense animus that some multi-hull owners feel toward mono-hull owners. Please know that it is not reciprocated on my part.

I guess haters will be haters no matter what stripe they wear!

I agree and if you look at my post history you'll see it is the first time I have called anyone out. Everyone has an opinion, as it should be, but some ( not you Liam ) want to make snide comments on a repeated basis. You're right, "why take the bait?", is a valid point. My answer is eventually even a grain of sand makes an oyster burp a pearl. Looking at the post history of some it is obvious they are a negative influence on many. When someone opens themselves to the moniker of a "newbie" and seriously wants help it is annoying to have some uninformed poster drag things off topic just to see their post number go up.

I hope the OP, asking for information on catamarans gets good, pertinent, first hand knowledge. Getting pooped is a serious subject. Mis information can make for poor decisions. Thank you for bringing to my attention that responding to the haters is just fuel for their misguided fire.

[Sailing55]

Originally Posted by duefocena

I agree and if you look at my post history you'll see it is the first time I have called anyone out. Everyone has an opinion, as it should be, but some ( not you Liam ) want to make snide comments on a repeated basis. You're right, "why take the bait?", is a valid point. My answer is eventually even a grain of sand makes an oyster burp a pearl. Looking at the post history of some it is obvious they are a negative influence on many. When someone opens themselves to the moniker of a "newbie" and seriously wants help it is annoying to have some uninformed poster drag things off topic just to see their post number go up.

I hope the OP, asking for information on catamarans gets good, pertinent, first hand knowledge. Getting pooped is a serious subject. Mis information can make for poor decisions. Thank you for bringing to my attention that responding to the haters is just fuel for their misguided fire.

Not real clear who you are responding to as you are quoting two comments, but you are spot on. And you are right with the pearl analogy, some things can be extremely irritating and a little release can be a good thing. Now that is an area in which I claim a great deal of experience!!

"Non illigitimus corborundum"
Farley Mowat

[OceanSeaSpray]

Originally Posted by rabbi

Cats act different than a heavy mono in following seas. They accelerate faster and the transom lifts faster. That is simple physics (weight, moment of intertia and all that).
Monos get pooped by following seas, cats normally not.

That's really funny, because it hasn't managed to happen to me in over 70000NM, a large part of it in the high latitudes... they always curled and broke some distance aft without being able to get close.

Actually, whether you get caught or not by the wave has nothing to do with the number of hulls:

1. The boat needs to be buoyant enough aft to lift the stern and start "heading down the hill"
2. It needs to be able to accelerate and stay in front of the wave while it is too steep/breaking and would climb aboard if it caught up

There are plenty of monohulls that do that every time and I can think of plenty of multis that don't exactly do it too well, and vice-versa, all for the exact same reasons.


Because the weight of the boat contributes equally to both the forward drive "downhill" and the resistance, light or heavy doesn't make that much difference. It really comes down to hull shape and, if anything, this can place modern monohulls at an advantage because they tend to offer a larger aft waterplane area, a larger flat run and more volume forward if needed. They start picking up the wave earlier and breaking crests seem to stay further away from the stern.

There is a more complete discussion presented here and, while multis are not specifically mentioned, the sea and the physics are the same for everybody.

You only ever get pooped if you can't outrun the crest, all boats try to run and some don't succeed; this is irrespective of the number of hulls.


The question from the OP has merit and I think the answer could vary a lot with what you do with the boat and where you intend to sail it.
I have personally seen waves "hit" offshore and trust me, if one managed to find a wide vertical surface like what is found on the boats discussed here, the way it is constructed wouldn't make much difference. It would walk straight in without asking for permission.

[ZULU40]

Originally Posted by Liam Wald

Honestly, I was just commenting on "sliding glass doors" on boats.
I have nothing at all against multi-hulls. I just don't think that big patio style sliding glass doors are very good on sea going boats whether mono-hull or multi-hull.

What came as a really big surprise to me is the intense animus that some multi-hull owners feel toward mono-hull owners. Please know that it is not reciprocated on my part.

I guess haters will be haters no matter what stripe they wear!

I dont feel Im especially in either camp

I just point out that boat design brings with it failings. If the sliding glass doors on multis AND monos doesnt grab you, the open transoms trending on racing boat design should.

[buzzstar]

Originally Posted by 44'cruisingcat

Brad, I think it's fair to concede that when it comes to poop, the mono guys are the experts.

We mono guys do know poop when we read it, and realize the source of most of the pooping is the cat people. Mostly kidding in good fun.

More seriously, I do think (but not know) that a mono below, say 40' is more susceptible to being pooped than a cat of similar length. I've been on a mono at the helm when she was pooped (very wet, managed stay on board and not broach) but not a cat.

I wonder if the older mono designs, where the transom was well above the usual water line and out of the water has something to do with this.

[OceanSeaSpray]

Originally Posted by ZULU40

I dont feel Im especially in either camp

I just point out that boat design brings with it failings. If the sliding glass doors on multis AND monos doesnt grab you, the open transoms trending on racing boat design should.

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.

Many of the big cruising cats we see more and more today are primarily good weather, downwind boats in the sense that their features are intended to support this type of use with plenty of time at anchor as well.
No point engaging in horrific arguments about whether they are all weather, all conditions sea boats. They were never even envisioned this way. They are a by-product of Trade Wind cruising. Now it doesn't mean that plenty of other things shouldn't be done with them, but there clearly are some that can't be done: just look upwind.

If a design aspect is only going to be acceptable "up to a point", you can bet that you can find conditions where it is not going to be alright any more. In the end, you decide and it is your own responsibility to remain within the envelope afterwards. It is just silly (and dangerous) to come back and suddenly claim that the limit doesn't in fact exist.

[Southern Star]

Oceanseaspray you are correct - as I pointed in post#7, there are monohulls such as Open 60's whcih can perform as well (and as safely) as most catamarans because they mimic catamaran design: extreme beam with relatively flat underbodires and twin canting rudders create more bouyancy and form stability aft. You are incorrect, however, in concluding that the typical cat and mono have the same dynamics:

1. Cats typically have hulls extending aft well behind the bridgdeck/cockpit which increases the leverage of that bouyancy. How many monos with wide after bodies have their transoms well aft of the cockpit?
2. It is not just bouyancy in the hulls of a cat that creates lift in a following sea - the aft end of the bridgedeck can also create lift when approached by large following seas. Look at the picture of the Lagoon 380 and you should be able to envision what I am talking about.
3. Apart from Open 60's and the like (which can and do surf), most cats are able to surf in large following seas with minimal risk of broaching. Check out youtube videos of even small 'condomarans' like the Lagoon 380 safely hitting 16 knots plus downwind in the Southern Ocean to see what I am talking about.

As I pointed out in an earlier post, please report to us the multitudinous cases of sliding glass doors imploding on cats that surely must exist if you are correct. Or perhaps read what Barnkiel (a vastly experienced monohuller/boat service contirbutor to this site) said in post 17.

And to those who consider multihullers overly sensitive I say this. Few, if any of us, without significant monohull experience, post on the monohull threads. When we do, it is not to make ignorant blanket statements attacking the breed. We do not start the equivalent to recent illogical, obviously incorrect and inflammatory threads such as 'Why do catamarans motor nearly 100% of the time?"

Theorizing about the dangerousness of sliding doors on cats without experience or evidence to support those theories is sadly typical, although it has become very tiresome.

Brad

[StuM]

Originally Posted by dagranger

Never owned a Cat but have sailed against them in Races off So Cal. Was witness to Imi Loa about 43 ft. cat being turtle and needed rescue for the crew. However the boat had nothing to do with capsize..according to owner Vic Sterns they were carrying too much sail and good strong force of wind caught them as they were on rise of swell and caught them under the hull, over..with all that said the boat was recovered and reoutfitted and still sailing in races all over So Cal..several trans pacs...winds at start were 25 to 30 and we had 45 across the deck most of the time not a good day to go racing which after 2 hours was called off..I don't know about all cats being built but if the build is good they will go anywhere at anytime and get their quicker with a whole lot more room..anyone thinking otherwise is just no willing to look at reality..Good Luck Don Friday Hrbor whitney series san nicolas island race 1974

Choydesign - Imi Loa For Sale
Goodbye | Imi Loa 2012

1963 CSK Rudy Choy Design | eBay

It's easy to see why she could turtle if mishandled.

"She is a beautiful 43' CSK catamaran built on the west coast an
d launched in 1963, originally built for Vic Stern as a cruiser/racer. "

Look at the very high LWL/Beam ratio (43:18) and narrow hull beams on it. Not very stable at all.

It will turtle much easier than a modern cruising cat. There is a reason why modern cruising cats tend to be have beam greater than 50% of LWL.