Lithe or Large - displacement by the numbers

[SVNeko]

Originally Posted by caveman22

The dagger boards make a huge difference to the Atlantic Cat I race on which has had the mini keeps removed. They provide both lift and pointing ability. Wonder if they are worth the risk in a cruising environment ? Yes we hit a reef with a daggerboard down doing 14 knots and it was not pretty. We managed to get the board up and strapped to continue the race but a proper repair was a mayor exercise that I dont think would be possible in a remote pacific location.

We hit an uncharted rock in the Las Perlas in Panama and crunched up our daggerboard. Not impossible but not an easy fix. However, it has not put us off daggerboards. We'd never have a cat without them.

[Stumble]

Originally Posted by Symphony

For the lighter cats, are there considerations for trim between hulls? Such as balancing
dive compressor, appliance and freezers, laundry machines, air conditioner compressor and pump, Battery bank.

This is true for all boats. You want them to sit level. Any good designer has done this out of the box via detailed weight studies and placing equipment correctly in the first place. It is up to the owner to make sure it stays that way.

The same thing is true of for and aft trim, but on some cats you may want increased weight in the stern to keep the bows up while deep reaching. Ideal is movable ballast, but that's a little silly for even performance cruisers.

[Jim Cate]

Originally Posted by Symphony

For the lighter cats, are there considerations for trim between hulls? Such as balancing
dive compressor, appliance and freezers, laundry machines, air conditioner compressor and pump, Battery bank.

Well, if you put all that stuff on a 'lighter cat' it has ceased to be a light cat!

Jim

[Symphony]

HA.

I am thinking of a 40-51 catamaran. could still be light but carry that much "stuff?"

[caveman22]

Originally Posted by 44'cruisingcat

It's easy to make the bottom 1/2 metre or so of a daggerboard "sacrificial", ie a foam core with light glass over it, which will just break off in an impact, and can be easily replaced.

Consider hitting a reef at 14 knots with a minikeel...


Come to that, you were sailing to windward at 14 knots? Don't you know cat's can't do that?

Sounds like a good idea but would require some engineering.The boards get really loaded up.

I do like the idea of both dagger boards and mini keels such as on the Switch 51. Have not head of this boat before SV Neko commented. Looks like you get both and it appears the ability to beach. Interesting looking performance cat.

I wish I had $ 2m for Kato but sadly out of my price range. Maybe with depreciation in 4 yrs ?

[Brob2]

To go back to the original question, manufacturers and designers displacement calculations are not dissimilar to automobile horsepower calculations; some are more accurate than others. I believe cruising boat producers are more likely to overestimate a boats displacement while a racing design is more likely to have it underestimated, both scenarios being optimistic guesses, but from different perspectives.

[REsCat]

Originally Posted by caveman22

Sounds like a good idea but would require some engineering.The boards get really loaded up.

I do like the idea of both dagger boards and mini keels such as on the Switch 51. Have not head of this boat before SV Neko commented. Looks like you get both and it appears the ability to beach. Interesting looking performance cat.

I wish I had $ 2m for Kato but sadly out of my price range. Maybe with depreciation in 4 yrs ?

Caveman, my boat has mini keels as well as db's and I am very glad I have both for many reasons but beaching my Cat is not something I would ever consider or was a must have ability on my boat search priority list.
These mini keels were part of a system that Catana offered for my generation of boat called "magic legs". This system was an expensive option that some ordered for the purpose of "beaching" but few in practice ever did and most owners had the front "legs" part of the system removed. The aft "mini keels" were ordered for my boat by the first owner for all the reasons that I value them for.
I know there are a few well designed db performance cruising Cats with "beaching" capability with flip up rudders and outboards(hence no saildrives) but it would seem to me that a Lar keel performance cruising Cat is maybe a more viable and realistic option for many that want a reasonable, safe "beaching" quality and I have seen photos of such submitted here on CF and elsewhere.
Like Neko, I would never own a Cat without dbs, I love mine but am very careful using them as I am sure he and every one with them are and so far have (lucky?)avoided crunching one. I have too many other things to fix or improve and spend money on.

Bob

[SVNeko]

CW Atlantic cats have a bit of keel along with boards also.


Sent from my iPad using Cruisers Sailing Forum

[caveman22]

Originally Posted by REsCat

Caveman, my boat has mini keels as well as db's and I am very glad I have both for many reasons but beaching my Cat is not something I would ever consider or was a must have ability on my boat search priority list.
These mini keels were part of a system that Catana offered for my generation of boat called "magic legs". This system was an expensive option that some ordered for the purpose of "beaching" but few in practice ever did and most owners had the front "legs" part of the system removed. The aft "mini keels" were ordered for my boat by the first owner for all the reasons that I value them for.
I know there are a few well designed db performance cruising Cats with "beaching" capability with flip up rudders and outboards(hence no saildrives) but it would seem to me that a Lar keel performance cruising Cat is maybe a more viable and realistic option for many that want a reasonable, safe "beaching" quality and I have seen photos of such submitted here on CF and elsewhere.
Like Neko, I would never own a Cat without dbs, I love mine but am very careful using them as I am sure he and every one with them are and so far have (lucky?)avoided crunching one. I have too many other things to fix or improve and spend money on.

Bob

Thanks for your comments Bob.

The ability to beach sounds useful in theory but I was wondering if in practice it is used - doesn't sound like it.

How do you find the Catana 471 ? I chartered a 42 carbon out of New Caledonia and did the 60 odd nm mile beat down to Is Pines. Pusing against 25-30 knt Trade winds and 2-3 m swell it was not pleasant however the run back to the main land a week later was awesome. The boat felt rock solid and really enjoyed it. I did have my concerns about the relatively exposed helm positions if got really messy and autopilot was not an option. Also storage was a bit light on. How do you find the 471 ?

[REsCat]

Originally Posted by caveman22

Thanks for your comments Bob.

The ability to beach sounds useful in theory but I was wondering if in practice it is used - doesn't sound like it.

How do you find the Catana 471 ? I chartered a 42 carbon out of New Caledonia and did the 60 odd nm mile beat down to Is Pines. Pusing against 25-30 knt Trade winds and 2-3 m swell it was not pleasant however the run back to the main land a week later was awesome. The boat felt rock solid and really enjoyed it. I did have my concerns about the relatively exposed helm positions if got really messy and autopilot was not an option. Also storage was a bit light on. How do you find the 471 ?

I am into 8+ years with it so I guess it agrees with me . I love my boat and at times I hate my boat. When we are sailing, passages, fighting any kind of weather, cruising to new places, sitting at anchor... we are glad/thankfull we own this boat.
When I am redoing/re-engineering all the wiring and plumbing and other systems...then I develop some hate.
But to be fair its not the boats fault but the people who engineered and installed the systems... its a French thing...
The boat sails and handles superbly well and is very, very simple and when you own one or study one in depth and compare it to other boats feature by feature this becomes very apparent imo.
We keep our boat simple and light, as we are comfortable with this and when the wind puffs up or down we feel it. It has mechanical steering which we love for the rudder,water sense.
The outboard helms are one of its best features and many here would shun them but until you actively sail, cruise, passage, dock etc etc you won't appreciate this.
I would not buy a newer generation Catana for many reasons but opt for a new gen Outremer if I was seeking a newer boat, which I am not.

"Pushing against 25-30 knt Trade winds and 2-3 m swell it was not pleasant"

Were you motoring or sailing and would this have been pleasant in any boat?

Bob

[44'cruisingcat]

Originally Posted by caveman22

Sounds like a good idea but would require some engineering.The boards get really loaded up.

I do like the idea of both dagger boards and mini keels such as on the Switch 51. Have not head of this boat before SV Neko commented. Looks like you get both and it appears the ability to beach. Interesting looking performance cat.

I wish I had $ 2m for Kato but sadly out of my price range. Maybe with depreciation in 4 yrs ?

Engineering for the bottom 1/2 metre of a daggerboard? Are you kidding? Foam with 400 gsm double bias glass would be more than ample for normal sailing loads. But easy enough to break off in a grounding, without damaging the case.

To be honest, if you're going to have minikeels, may as well not bother with daggerboards. You sacrifice a major advantage of daggerboards, which contrary to popular opinion is NOT sailing to windward, but is the reduction in drag on every other point of sail. Just my view.

[44'cruisingcat]

Originally Posted by caveman22

Thanks for your comments Bob.

The ability to beach sounds useful in theory but I was wondering if in practice it is used - doesn't sound like it.

Some do, some don't. We probably spend around 2 months per year in anchorages where we dry out at low tide. These are our favourite anchorages.

A friend of ours hasn't slipped his boat in 10 years, does all his maintenance on the bottom. We slip to antifoul, but do engine maintenance, lube rudder shafts, bottom scrubs and touch-ups while dried out. Polishing hull sides too.

Many people I know do similarly.

[downunder]

Originally Posted by caveman22

Thanks for your comments Bob.

The ability to beach sounds useful in theory but I was wondering if in practice it is used - doesn't sound like it.

As 44c said there are many many great anchorages around Australia where the ability to beach is a major advantage,

[REsCat]

Originally Posted by 44'cruisingcat

To be honest, if you're going to have minikeels, may as well not bother with daggerboards. You sacrifice a major advantage of daggerboards, which contrary to popular opinion is NOT sailing to windward, but is the reduction in drag on every other point of sail. Just my view.

44c while I agree with the daggerboard "plus" I totally disagree with the DBs and minikeels cancelling each other out as it pertains to how they are implemented on my boat.
I obviously can't speak for other boats with both as I am not familiar with them.
If you saw the size and profile of mine, where they are located, the many benefits they give, and if you sailed my boat on a thorough, long term basis,
you would not make that assertion.

Regarding beaching, I was alluding to your boat (with photos I believe you have posted) with my reply to Caveman above and I recognize that AUS particularly the East coast offers many excellent ,potential beaching oportunities. That is not the case with much of the rest of the world I believe.

Bob

[tp12]

I'd add that the Schionning designs are daggerboards, can have kick up rudders and be beachable without mini-keels.

I'm thinking outboards, kick-up rudders and daggerboards. I can't see a circumstance when you'd need to jump in the water to free yourself of anything.