Cat - Rising water failure modes

[Rustytony]

Hi folks, I’m researching for a future purchase... leaning towards a Leopard 45.

One thing that occurs to me as a potential differentiator for the production cat might be how they handle taking on water.

For instance if batteries were all in the lowest spot that would be a fail. I am sure they are not. But how the cats handle say a cracked through hull might be different for different manufacturers.

All wiring up high and perhaps designed for protecting critical systems would be a win.

Does anyone have any thoughts on the production cats design as they settle down into water? Do they maybe differ in a reef strike survivability? Rudder post leak?

Just trying to see if the failure mode designs are significantly better or worse for any particular brand.

[Barra]

Not all cats have watertight bulkheads for starters. One in particular to look at is the engine bay where a sail drive failure spreading into the rest of hull can be avoided but often is compromised.

I've seen plenty of batteries mounted low due to center of gravity benefits but yeah water damage is the trade off.

If survivability concerns are high on your list I'm not sure why the new leopard designs with the potential stability problems from that huge water catching bucket up forward are high on your list though. Much safer designs out there if you are going where these things matter....

[Chotu]

Yeah. I definitely wouldn’t be looking at a production cat like that if I was concerned about the things you’re talking about. They are not designed for that stuff.

[gmakhs]

It's gonna be difficult to find a sea worthy catamaran, leopards and lagoon's are not .
There other that are.most important is that maybe you can purchase a production catamaran and you can do small modifications .

[Fixer]

Yeah, those “front cockpits” like on the Aquila 48 scare me. Taking on water over the bows could be catastrophic.

[Rustytony]

Thanks for the replies but I probably disagree a little bit... Leopards have been delivered on their bottoms from CapeTown to all over the world. There is plenty of discussions around this forum about blue water capability of prod cats...

let’s put that aside for the moment.

As to the idea they are not designed for considering taking on water... well why the hell not? there’s teams of people working full time on their designs...

Actually I dont think it’s true that no thought or design on that has happened. Some, for instance, have water tight engine compartments and bow crush bulkheads.

So I guess I’m really asking those that have or know well a fairly recent prod cat... what do you think of your boats rising water survivability?

Will critical systems fail and water spread before you can have a chance to control it? (Obviously that’s an unknown and wildly variable, but just as a rough first approximation type thing...)

Thanks for any thoughts or inputs... even the ones poo-pooing prod cats...

[Barra]

Originally Posted by Rustytony

Thanks for the replies but I probably disagree a little bit... Leopards have been delivered on their bottoms from CapeTown to all over the world. There is plenty of discussions around this forum about blue water capability of prod cats...

let’s put that aside for the moment.

As to the idea they are not designed for considering taking on water... well why the hell not? there’s teams of people working full time on their designs...

Actually I dont think it’s true that no thought or design on that has happened. Some, for instance, have water tight engine compartments and bow crush bulkheads.

So I guess I’m really asking those that have or know well a fairly recent prod cat... what do you think of your boats rising water survivability?

Will critical systems fail and water spread before you can have a chance to control it? (Obviously that’s an unknown and wildly variable, but just as a rough first approximation type thing...)

Thanks for any thoughts or inputs... even the ones poo-pooing prod cats...

Well there are 2 kinds of sailors out there - ones that have had serious green water over their bows and the ones that havnt.

The former would not consider the kind of design you are talking about if they have plans to take their boat where it might see those kinds of conditions. Full stop.

Remember these designers you are putting all your faith in won't be there with you.

If your just planning on island hopping then don't sweat it or the rising water issue. All of them are capable of dealing with short term water ingress even if you are down an engine.

[jmh2002]

I'll stir the pot, even if it's with an option that is probably not exactly your preference...

Wharram catamarans have design features that address many of the points that you have raised:

- the hulls are sectioned into compartments and accessed from deck level automatically creating a higher level of watertight integrity (to what degree depends on the build).

- they have stern hung external rudders so no possibility for an internal leak and simplifying repair and maintenance.

- they tend to be powered by outboards mounted in retractable pods preventing any leak from a sail drive or propeller shaft (and reducing drag under sail)

- they are of timber construction which is naturally buoyant

- they have a more open deck design with netting and slatted decks, especially forward, to reduce pounding as well as dissipate solid water from both above and below.

- etc, etc

[Palarran]

Originally Posted by Rustytony

Thanks for the replies but I probably disagree a little bit... Leopards have been delivered on their bottoms from CapeTown to all over the world. There is plenty of discussions around this forum about blue water capability of prod cats...

let’s put that aside for the moment.

As to the idea they are not designed for considering taking on water... well why the hell not? there’s teams of people working full time on their designs...

Actually I dont think it’s true that no thought or design on that has happened. Some, for instance, have water tight engine compartments and bow crush bulkheads.

So I guess I’m really asking those that have or know well a fairly recent prod cat... what do you think of your boats rising water survivability?

Will critical systems fail and water spread before you can have a chance to control it? (Obviously that’s an unknown and wildly variable, but just as a rough first approximation type thing...)

Thanks for any thoughts or inputs... even the ones poo-pooing prod cats...

Leopards are now delivered via freighters and offloaded in certain spots. But the old ones were, along with almost all cats produced. More than a few didn't make their first crossing.

There are so many more important features to be concerned about compared to the location of batteries with a flooded boat as to make this concern nill. As others have said, having watertight bulkheads is the first and by far most important line of defense for controlling flooding. With my cat, I have a stern area, engine bay, main hull, and forward crash bulkhead. Only the main hull would make me freak out if it was flooding and we have two very large independent bilge pumps per hull for these areas. Also, the bottom of the hull is only about 14" below the waterline anyway so the ingress of water isn't going to be firehose level.

[Kenomac]

To say that Leopard catamarans are not seaworthy would be obsurd. If I’m not mistaken, are they not all delivered by hired crew from South Africa to most everywhere in the world?

[Palarran]

You are mistaken.
https://www.facebook.com/LeopardCata...type=3&theater

[BigNut]

Where is the popcorn? I need some before I pull up this here chair closer to the front.

[Chotu]

Originally Posted by Kenomac

To say that Leopard catamarans are not seaworthy would be obsurd. If I’m not mistaken, are they not all delivered by hired crew from South Africa to most everywhere in the world?

Nobody is saying they aren’t seaworthy. They just aren’t designed at this level the OP is talking about.

This is a different realm of safety beyond most production boats.

The biggest safety feature of all is buoyancy. How much weight is in that thing, versus what the buoyancy of the hull materials are, when holed.

Also the ability of water to move from one hull to the other inthe event of one of them breaching in the main section.

These sorts of design thoughts are not too high on the radar for these production catamaran builders.

[MikeFergie]

Why is it that people that have never even sailed on a boat have the most to say [emoji848]

Take a look at this Leopard 44 delivery in the southern ocean (with its bath up front)
https://youtu.be/hQ-svmgOxqw

Few monos or other boats would cope so well ...
Nuff said they are good blue water boats

[Chotu]

Originally Posted by MikeFergie

Why is it that people that have never even sailed on a boat have the most to say [emoji848]

Take a look at this Leopard 44 delivery in the southern ocean (with its bath up front)
https://youtu.be/hQ-svmgOxqw

Few monos or other boats would cope so well ...
Nuff said they are good blue water boats

This has nothing to do with what the original poster asked. They asked what happens when you put a hole in the catamaran. Why don’t you drill a hole in the bottom of a leopard and tell me what happens. I’ll put one in the bottom of my catamaran and tell you what happens. Seriously. There will be a big difference.

You can sail any boat anywhere you want to. We are talking about the situation where there is a hole in the hull. And a leopard is not going to do well in that situation.