Hull slap-is it a problem

[topmast]

Sailed an aluminium cat to the Andamans .Short steep seas ,not overly rough or windy. Couldn't leave a coffee cup on the table .Slam? Like a herd of Volkswagons fighting for position. Later models raised the bridge deck to address the problem. Same season. friends were stuck in the islands Indian Ocean while trying to scrounge enough glass and resin to fix the under belly which was breaking up .South African fancy cat. Don't remember model. Could be that location and ability to hid in a marina helps the Cat reputation.

[Cherod]

Mine is like being inside a base drum !!! Very disconcerting tho apparently not a structural issue , can't believe that in its 20 year life it has not been pushed as hard as I I do and no signs of structural damage , when there is a sea runing it is dreadful inside but almost unnoticeable from the cockpit , sure it moves around a bit in big waves but basically quite stable ,,,, beneteau blue 2 , 36 ft x 20 ft

[Pilot90442]

To a64pilot
It's funny you suggest that. Your not the first!

I'm over my power days so to speak. I'm ready for things to slow down a bit. Peaceful and quiet. As you can tell I'm a pilot figure you are too. Always wanted to sail. Finally at a point in life where I can really think about it. Somehow doing that feels like I'm not realizing this dream. It is somewhat logical I'll give you that.

[a64pilot]

Originally Posted by Pilot90442

To a64pilot

It's funny you suggest that. Your not the first!



I'm over my power days so to speak. I'm ready for things to slow down a bit. Peaceful and quiet. As you can tell I'm a pilot figure you are too. Always wanted to sail. Finally at a point in life where I can really think about it. Somehow doing that feels like I'm not realizing this dream. It is somewhat logical I'll give you that.

I enjoy sailing Wife has come to like it's peace and quiet over hearing the motor.
However I'm not so sure that your Wife and sailing will go together as well, and you said you will likely motor a lot.
Well, nothing motors as well as a motor boat, and you will likely see some significant cost savings as all the rigging and Sails don't come cheap, and unless you motor a LOT, I bet motors are cheaper, and you don't worry much about bridges etc.
only Cat I have spent significant time on was a live aboard diving vessel, a big boat, and while it was usually stable, it had sort of a jerky, unpredictable motion in decent seas, so I'm thinking you guys will enjoy smooth water more than even moderate seas, hence the Power Cat. Wind and seas sort of go together.

I have never Chartered myself, but for you guys I think that may be the best idea, Charter a sailing Cat, with Capt if necessary, and try a Power Cat.

[Pilot90442]

My statement about motoring more then most needs a bit of clarification....

I said that in reference to being on a schedule. "I gotta get back to the marina this evening because I'm working tomorrow and the winds blowing in the wrong direction"...that sorta thing. No, we dont want a catamaran to run around on the iron genny. If that was the case then a power cat would be in order.

[harvey hellman]

No issue on our Lagoon 440

[danielamartindm]

Originally Posted by Cheechako

Hah! Had that experience coming out from the lee side of Grenada heading north. Once we got free of the island it was blowing 40 (apparent), no reef, and big steep seas tilting the boat with each crest.
That is what's scary about cats, you can be way over powered and not even know it... until you are upside down... although I knew it.

As you've said, when it comes to reefing and when to change point of sail for safety's sake, cats have to be sailed more "by the numbers" and less by the feel. I've been told that as far as strictly wind is concerned, my boat was designed to dismast before it would capsize. Of course, it's seldom the wind that does you in, it's the waves.

[Rapanui]

We have had 5 cats in the last 45 years and apart from one 24 ft one off with very low bridgedeck clearance, for us slamming is a non issue. Like the consensus here, virtually all production cats are adequate for slamming, it will occur in extreme conditions but infrequently. The point is, that when you reach the point where slamming occurs, its the boat motion in that weather that is the issue far more than the occasional slam. The main factor that determines boat motion is the hull shape.
To give an example, our 3 tonne 30 ft Sailcraft Iroquois had a destroyer hull form with moderate overhang bow, very fine deep entry and a gentle knuckle. It had a very soft ride, you could leave kettle on the stove (no fiddles), and a bottle on the table and they would not move. Very little pitching and little de-acceleration.
On the other hand our 3 tonne 32 ft FP Maldives had a vertical stem, flat entry and wide flat transoms. It was much faster but had a harsh ride both with the flat bow pounding like riding over cobblestones, and sharp de-accelerations, so much so that we broke 2 kettles by them shooting off he stove when the boat. We loved it, it was fast, just as seaworthy but a significantly worse ride.
Our 5.5 tonne 38 ft FP Athena has a similar hull shape to the Maldives but has a much easier motion, due in my view to the increased weight.
My advice would be to look at the hull shape, make a short list and then charter to see what works for you. Then, buy your choice and spend money on fitting plenty of grab rails to facilitate your wife getting round the boat as easily as possible. I have never seen a production cat with adequate handholds.

[Cheechako]

It's simple, cats slam when waves crest between the hulls. The two hulls are heading into troughs and the crest slaps the center. Depending on angle of sail and wave period it's better or worse. None are immune.

[a64pilot]

Originally Posted by Pilot90442

My statement about motoring more then most needs a bit of clarification....

I said that in reference to being on a schedule. "I gotta get back to the marina this evening because I'm working tomorrow and the winds blowing in the wrong direction"...that sorta thing. No, we dont want a catamaran to run around on the iron genny. If that was the case then a power cat would be in order.

Trust me, a schedule will have you motoring a LOT, number of hulls doesn't really play into it I don't think.
I just Retired, and before Retirement, that having to be back at work on Monday more often than not meant cranking the Yanmar and going. Not to be too obvious but to sail you have to have the right amount of wind, coming from the right direction. When you add a specific day into that, it is sort of a rare event.
Then add in the speed of the average sailboat, Cat or not and your sort of limited to a weekend range of about 50 miles, double or triple that amount for a powerboat.

However not much beats being under sail and making way with a nice breeze, maybe listening to good music and enjoying a cold one.
Really makes you hate Mon., and if you are like me it will get you into figuring out how to retire early.

I don't understand how either, but it doesn't matter where I want to go, that will be the direction the wind is coming from, we are always beating to windward. I have just come to expect it.

[44'cruisingcat]

Simple answer - no, it's not a problem.

[billnb]

Originally Posted by Pilot90442

I thank you all for your input. I think it best to let it be known where my wife and I come from in our situation so you can better understand our concerns.

We are 50 yo almost empty nesters. Grew up in Chesapeake Bay area around Norfolk Va. My wife grew up in Miami. We have both been around power boats off and on much of our lives. Quite a bit of camping over the years too. This is the logical next step. Combine boating and "camping" on the water��. Aka Catamaran!

Wife has mobility issues due to a lower back injury that cost her career as a nurse. I am a major airline pilot with east coast bases to choose from. I will continue to work as we live aboard but I can move up and down the east coast from base to base and become "snow birds" while still working. We are not going to be crossing an ocean any time soon. I can commute from almost anywhere from the east coast to the carribean without much difficulty.

My wife's mobility issue drives this. Having her get "slammed" around is a concern. Her comfort is key. We will be in marinas(no slamming concern there) since i will continue to work but we would take trips when I have more then a few days off at a time. Probably motor more then most because of that schedule (slamming concern here because conditions don't follow my schedule).

As you think of the slamming issue think of it the terms of how it affects a person with these issues. Also think in terms of coastal cruising/island hopping. Are we making it a "problem" in our mind or is it one to really worry about?

I am thinking of starting a new thread asking for safety/design input of different cats for a person with mobility concerns.

All cats will slap given the right conditions.



If you're worried about wifes comfort though, any cat will be far more comfortable than a monohull, both at anchor and sail.

[Nahbrown]

Originally Posted by harvey hellman

No issue on our Lagoon 440

Really? We have hull slap that is loud.

[Factor]

Originally Posted by Pilot90442

I thank you all for your input. I think it best to let it be known where my wife and I come from in our situation so you can better understand our concerns. .

Perhaps look at boats other than the so called Big Three.

[jzk]

I bought a Leopard 47 in Grenada and sailed it to Fort Lauderdale in all sorts of conditions. There were times where we would get an unsettling "bang" from below that seemed to be just wrong. It wasn't so bad that it would bounce anything up from the table. I spoke to a crew on a Voyage 440 who told me they had excessive, concerning slapping.

We got used to it. As a monohul sailor, I am just not used to "hitting" things like that.

Again, we got used to it. I wouldn't cross a boat off the list over it, but I can't say I wouldn't prefer less of it.