Multihulls that don't slam

[zboss]

Originally Posted by Highland Fling

Lagoon 420/421 AND most of the newer Lagoons too

There is a 420 next to us right now... it looks to have a middle section with the hull configuration of a trimaran.

Originally Posted by savvy

http://api.ning.com/files/HbsRLQ*GNX...737&height=493

this boat.

Oh.. that is nice... what kind of boat is that?

[monte]

Originally Posted by Wendi

Wow, I am still laughing. Brings back memories. This is a very accurate and amusing description of how it feels to sleep in the cabin. I always enjoyed that sledge hammer that was being slammed to the hull next to my head. That was in a wonderfully orchestrated concert with all of the above dwarfs and sounds described. Those last 6 days were relentless. 18' seas and squalls to keep me humble. But the noises, oh the noises.
There were the beautiful silent nights of smooth seas and the only sound is the breath of the dolphins who have come to swim alongside. It is all worth it.

Yes Wendi. Are you coming down to the Caribbean for a sail soon?
Oh and swimming at Guadeloupe with the dolphins the other day was amazing, listening to them talk underwater was...wow!

[monte]

Originally Posted by zboss

There is a 420 next to us right now... it looks to have a middle section with the hull configuration of a trimaran.



Oh.. that is nice... what kind of boat is that?

The 420 was a bit different in hull design to the rest of the Lagoons. The idea of the 'gull wing' bridgedeck was to break the waves and not give them a flat surface to slam against. I'm a bit surprised at the mention that they slam less as they seem to be quite low in the centre, but hey, if it works it's all good!

[sailsw00]

All cats will pound, but with greater bridgedeck clearance there's less pounding. Catanas have lots of clearance: I can run my dinghy, with motor, between the hulls, and it pounds far less than most cats, which is one reason why I bought it.
-Steve

[arsenelupiga]

see Lagoon 39.

Narrow space between hulls, fat hulls, high clearance.

I suspect slam virtually eliminated. Lagoon 400 slams very little although much wider space between hulls. I don't consider it an issue at all.

Test sailed Catana 431, definitely more slamming.

[Boatguy30]

Originally Posted by zboss

There is a 420 next to us right now... it looks to have a middle section with the hull configuration of a trimaran.



Oh.. that is nice... what kind of boat is that?

I reckon the Prout Brothers must be smiling from wherever they are at the new Lagoons. They basically scaled up Prouts with squared up ends.

It's amazing to me almost all the new designs seems to have totally given up on performance and just put in bigger engines.

Have a look at my blog for a recent photo of us racing upwind into 4-5' seas in Exuma sound with commentary from my wife and a former PDQ sailor. Pity more of the multis didn't race in Georgetown, but it did involve hoisting sails AND turning off the motors!

[Barra]

A non slamming cat is a complete myth IMHO. Like cheech said sometimes conditions are such that seas just mount up under your bridgedeck and slam into it. No way fat hulls more clearance etc will stop that type of wave action. More routine slapping usually from sailing to wind can be reduced with other compromises but really a bit of a slap is nothing to worry about

Anyone who says their cat doesnt slam just hasnt been in those "right" conditions yet.

[smj]

Something that's being overlooked is overloading. I have a friend who owned a PDQ 36 with diesels and every available option you would want, also had a lot of personal gear onboard. He said his boat would pound badly going to windward. Our PDQ 36 has outboards and is intentionally kept light. We have sailed upwind in 20-25 kts and 3-4' Hawks Channel square waves and didn't pound. The PDQ 36 has a waterline beam to waterline length ratio of over 11:1 which means if kept light she will sail well, but if overloaded the performance goes down and a better chance of pounding the bridgedeck.

[2Hulls]

I agree with the assertions that no cruising cat is immune from slamming. Some are just more prone to it than others for the reasons already discussed.

I will note, however, that the few jarring bridgedeck slams I've experienced on my boat were off the wind in offshore boisterous conditions. I don't specifically recall any significant slams sailing upwind. Maybe it's my aging memory.

It seems to take that "perfect storm" circumstances of the wrong combination of seastate, boat speed, position in the wave train, etc., etc., etc.

Wave slap on the hulls is another phenomena altogether, IMHO, and no cruising boat is immune from this.

Dave

[Highland Fling]

Originally Posted by 2Hulls

I agree with the assertions that no cruising cat is immune from slamming. Some are just more prone to it than others for the reasons already discussed. Dave

Sorry but factual evidence does not support that opinion.

Did you read my post?

Upwind downwind and across the wind and seas in up to 35 knots of wind typically 25 plus rounding St Martin/Sint Maarten and racing in the Caribbean seas in the 35th Heineken Regatta the L420 DID NOT SLAM ONCE.

The Gull Wing Bridge deck DOES eliminate slamming and you dont get more 'cruisie' than a Lagoon. The older Lagoons the L380 L42 L47 and even the L570 do slam.

In fact the L570, well it does not slam it has a troll who lives underneath the bridge deck with a big big sledge hammer.....

I don't I hope need to add I have no axe to grind here as I sail a monohull at the moment.

I am just giving real time feed back on (the lack of) slamming on a L420 and yes I was both surprised and amazed that it did not slam at all.

[smj]

I would also suggest that slower catamarans don't slam as much as they aren't pushed quite as forcibly through the water.

[Highland Fling]

[QUOTE=smj;1819150]I would also suggest that slower catamarans don't slam as much as they aren't pushed quite as forcibly through the water.[/QUOT

Really!!! we were racing and doing 8+knots VMG towards a windward mark in 26 gusting 35 knots of wind in a horrible Caribbean sea state. I don't see how much worse it would have been unless it had been survival conditions.

Believe you me, {the owners wife told me when I signed on as helmsman that she was expecting (hoping) that we did not come in last}....

I was pushing that cat as hard as I could do and it was sailing at something very very close to its maximum all the time, in weather that no cruiser would have chosen to go out in.

The only way to make it go faster would have been to dump a few tons of cruising gear and quickly swap the BIG Fixed props for feathering or folding ones and put a new brand suit of sails on it

The riding turn issue could have been solved if we had three powered winches as we were cross winching when we tacked to use the one powered winch which was a bit of a disaster.....mind you sheeting and adjusting the sails by hand would have been another problematic area.

We had one crew member with a very bad case of mal de mer, we beat so many other cats in the faster class because they gave up (retired from the race) going to windward as the conditions were so extreme and horrible.

These other cats that retired probably had severe slamming issues

[Highland Fling]

Originally Posted by zboss

There is a 420 next to us right now... it looks to have a middle section with the hull configuration of a trimaran.



Oh.. that is nice... what kind of boat is that?

tis a Wharam cat I don't know what model though but as most of them are home built could be any model.

IT looks quite like a Tiki 46 with modifications but with that picture and no person in shot it is difficult to scale and size the cat

[smj]

[QUOTE=Highland Fling;1819170]

Originally Posted by smj

I would also suggest that slower catamarans don't slam as much as they aren't pushed quite as forcibly through the water.[/QUOT

Really!!! we were racing and doing 8+knots VMG towards a windward mark in 26 gusting 35 knots of wind in a horrible Caribbean sea state. I don't see how much worse it would have been unless it had been survival conditions.

Believe you me, {the owners wife told me when I signed on as helmsman that she was expecting (hoping) that we did not come in last}....

I was pushing that cat as hard as I could do and it was sailing at something very very close to its maximum all the time, in weather that no cruiser would have chosen to go out in.

The only way to make it go faster would have been to dump a few tons of cruising gear and quickly swap the BIG Fixed props for feathering or folding ones and put a new brand suit of sails on it

The riding turn issue could have been solved if we had three powered winches as we were cross winching when we tacked to use the one powered winch which was a bit of a disaster.....mind you sheeting and adjusting the sails by hand would have been another problematic area.

We had one crew member with a very bad case of mal de mer, we beat so many other cats in the faster class because they gave up (retired from the race) going to windward as the conditions were so extreme and horrible.

These other cats that retired probably had severe slamming issues

I'm sorry, I wasn't trying to point out your boat in my thoughts. Whether a cat is naturally slower or whether a fast cat reefs, either way the chances of slamming should decrease.

[REsCat]

Originally Posted by 2Hulls
I agree with the assertions that no cruising cat is immune from slamming. Some are just more prone to it than others for the reasons already discussed. Dave

Originally Posted by Highland Fling

Sorry but factual evidence does not support that opinion.

Did you read my post?

Upwind downwind and across the wind and seas in up to 35 knots of wind typically 25 plus rounding St Martin/Sint Maarten and racing in the Caribbean seas in the 35th Heineken Regatta the L420 DID NOT SLAM ONCE.

The Gull Wing Bridge deck DOES eliminate slamming and you dont get more 'cruisie' than a Lagoon. The older Lagoons the L380 L42 L47 and even the L570 do slam.

In fact the L570, well it does not slam it has a troll who lives underneath the bridge deck with a big big sledge hammer.....

I don't I hope need to add I have no axe to grind here as I sail a monohull at the moment.

I am just giving real time feed back on (the lack of) slamming on a L420 and yes I was both surprised and amazed that it did not slam at all.

Actually, I fully support that opinion... and I will put my "factual evidence" against yours...give you some "real time feed back"...
I helped with a delivery of a friends' Lagoon 420 (06) from the Chesapeake to Charleston a few years back and soon after rounding Cape Hatteras our N at 15 turned into SW at 20-25kt "squares" against all the weather assurance that we had assembled.
We tried to soldier on but the "slamming", pounding, whatever you would like to call it (as I have referred to elsewhere in this thread) got so bad that the main fwd Hardtop supports started to separate from the hardtop and we had to jury rig to stabilize the situation and come up with an alternate strategy...the Gull Wing Bridge deck DOES NOT eliminate slamming...

We decided to try to go into Ocracoke Inlet which none of us had ever visited, in less than ideal conditions and this was after 8 hrs of misery.
It turned out fine and we carried on inside....
He sold the boat approx 6 months later for this and other reasons.
If we were in my boat we certainly would have suffered less pounding and slamming but it would still have been miserable.
I stand by my remarks of earlier that NO Cats are immune from slamming and pounding when the seas are lined up or confused against you.

Bob