New design performance catamarans are heavy - why is that?

[Matt Johnson]

Originally Posted by fxykty

I expect it is the much finer stern sections. Our bows are very full and underwater the run from the bow knuckle to max depth is straight. However, our sterns are very narrow - less than 30cm width where the sterns kiss the water. Newer boats carry max waterline beam pretty much all the way aft.

They are also way lighter with smaller rigs. In less than 8 knots upwind we’re under powered with our self tacking jib. That can lead to pitching when the boat isn’t fully powered up.

Every "buyer" of a performance catamaran we speak to talks of wanting light wind ability as a key selling detail. It was the motivator for us too. So we're going for a 18m rig instead of the 16m alternative. But this requires more structure to support the additional stress if caught with all sail up.... Which adds to weight. Maybe this is a newer buying motivation?

Remember the Seawind 1600 is a two decade old design. So closer to you than a new gen cat.

Another factor that I hadn't thought of previously was ISO CE certification and how that impacts build weight. Preciously, your gen of boats got low weights by not adding a lot of extras. But now buyers expect those things in their boats. And even with modern building technology CE requirements - which doesn't take into account a lot of newer ways to lower build weight - keeps weight up once the extras get added. If you look at a Schionning, you can get a nice low weight until you ask for CE certification.

[GreenWave]

Originally Posted by smj

This post is wrong in so many ways.
Light does not mean weak and heavy does not mean strong. The Lagoon is a heavy cat yet has had structural problems. Ours is a very lightweight build yet has had no structural problems. A lightweight cat built out of most probably expensive materials that have a high strength to weight ratio will probably be stronger than a heavy cat built out of inexpensive materials with a low strength to weight ratio.
The lightweight cat will be able to propel itself with a shorter mast, less sail area and much lighter sailing gear. This means the lighter cat will have less sailing loads on it plus it will sail on top of the waves rather through the waves which means less stress on the structure.

I don’t disagree with anything you said. I was attempting to give a partial answer to the OP’s original idea. No doubt every cat is different. Every manufacturers has different philosophy and priorities. Some go cheap, some go big, some use top quality materials others not so much. There is no one ideal answer and “heavy” is It just weight, displacement, and how low it sits in the water. I think that is part of your point.

[wingssail]

Originally Posted by smj

I think comfort is a personal choice as we much prefer the jitterbug over the waltz! Also the waltz brings on the uncomfortable and unnerving bridgedeck pounding.

There is another aspect to this. When your boat's motion (waltzing) is slow it means that your bows don't react quickly to a wave. It also means that you bury your bows a bit more, which means displacing more water and slowing yourself down. Jitterbug might seem jerky but it also means you are riding over the waves instead of plowing through them.

Of course this is the same for a monohull. If your boat is heavy, especially heavy in the ends, you will plow deep in the troughs and rise high over the crests. That motion is slow and not comfortable. On the other hand you can take your lighter boat, crack off in the waves, and go faster with an easier motion.

That's upwind. Downwind the motion is a bit different but the same principle applies. To go fast you want to splash less water aside, you want to ride over the waves instead of trying to flatten them out.

[chrisr]

Originally Posted by fxykty

Hang while damp. Can also put under under your mattress, but that could lead to mould.

How about changing material to polyester?

polyester ! good grief no, we're not savages you know...

cheers,

[PippaB]

Originally Posted by chrisr

polyester ! good grief no, we're not savages you know...

cheers,

Come now, if you won't wear polyester pants then you certainly mustn't sail a polyester boat with polyester sails.

[chrisr]

Originally Posted by PippaB

Come now, if you won't wear polyester pants then you certainly mustn't sail a polyester boat with polyester sails.

very true...wouldn't dream of it...so awfully gauche...

cheers,

[catsketcher]

I am not sure how many performance cats are built, many use infusion but I hope they use interior furniture for strength. Most custom performance cats are built as hulls first and then structural furniture is added. It is glued and tabbed on to provide a very light, stiff and strong web around the boat to increase stiffness and strength. It takes heaps of time but is the ultimate in terms of weight and strength. So you can be lighter and stronger IF your boats uses its interior well.

Some Lagoon issues and issues with other production cats can be traced back the lack of tying bulkheads and interior furniture to the decks and hull insides properly (or at all). Also some of the furniture itself is not highly structural - so you get a nice interior (although a friend's cat didn't have the bench tops touch the hull skin so you could lose things down the back of the cupboard) but you don't get any increase in stiffness and strength.

Whereas, the common owner built custom performance cruiser has almost all of the interior made light and tabbed onto the structure - reducing panel size, increasing stiffness and reducing problems with squeaking and doors not closing in a seaway. Every part is used to reduce movement and increase strength whereas some boats built to a timetable have drop in interiors with less attachment to the structure.

Young barnacles did a video on that - where a door would not close when close reaching. I tend to agree with Shayne as we come from similar backgrounds (although he is more experienced than me)

https://www.youtube.com/watch?v=QaiSzsP-Bas&t=4s

So weight does not mean strength and light can be stronger, if the interior is used properly.

[JC Reefer]

Originally Posted by GreenWave

I agree with this. From my perspective many of the past designs and builds were TOO LIGHT. That resulted in poorer quality and longevity plus look at the Lagoon bulkhead flex issues! Light may equal speed but it is often not synonymous with comfort and overall longevity.

Don’t see how lagoon is being listed in the Light or speedy category.

[Sos]

Maybe it's a bit like lifts (elevators!) in buildings - the faster the lifts get the higher the buildings are built.

Same with boats - electric winches, dyneema rope better deck equipment

[Giova]

Hi All,
My first post in the forum, so I hope I am not messing it up.

I have been following for some time the performance cruising cat discussions in the web and considering our plan to buy one for liveaboard in about 5 year time I started narrowing down some possible candidates.

The Current Marine CM46 (design from Schionning) is under the spotlight https://currentmarine.co.za/cm46/

However, as per the topic of this post, I am starting to evaluate if that would actually fit some of our requirements.

The specs are:

Length – 14m (46ft 2in)
Beam – 7.4m (24ft 4in)
Displacement – CE spec – 6 200kgs (13 640lb)
Bridge deck clearance – 0.95m (3ft 2in)
Draft – 0.5m
Mast length – 17-19m (56ft -62ft)
Mainsail area – from 62m2 (626sq ft)
Solent area – from 31m2 (333sq ft)
Staysail area – from 15m2 (151sq ft)
Code area – from 67m2 (677sq ft)
Engines – 2 x 30hp
Cruising speed under engine – 6.8 knots
Top speed under engine – 11 knots
Cruising speed under sail – 12-16 knots
Top speed under sail – 25 knots
Diesel tanks – 2 x 150lt (2 x 33 gal)
Water tanks – 2 x 250lt (2 x 55 gal)
Headroom on bridge deck – 2m (6ft 7in)
Headroom in hulls – 2m(6ft 7in)

They do not spec the Max load capacity but in the Schionning website it is mentioned 2,000kg.

Now, I have a couple of doubts (based on the fact that I am probably fitting right in the middle of the generations discussed in this thread - meaning I would require some comfort although not looking for large berths and definitely not flybridges ...https://www.cruisersforum.com/images...banghead.gif):

1) While I believe we could most of the time keep the boat light enough to comply with the 2,000kg spec, in case of ocean crossing, long distance passages, I guess we would add at least 500kg, possibly 1,000. Following what Schionning says in an interview, this is not a problem. Performance will gradually decrease but the cat will still be performing better than a cruising cat and will behave properly. Any thoughts? Any first hand experience? What scares me a bit is that from the pictures of hull#1, which is actually full carbon/non CE, it looks like the floating line is already under water.

2) As part of the required comfort features, there is noise insulation. I do not want to have a cat where all my energy is wasted in not being able to sleep or rest due to slamming noise or even excessive noise from the elements. Let me try to explain. In a couple of videos about a private built Schionning, and lately a review of the ORC57, comments raised on the extremely loud noise in the berths coming simply from the rain (???) or the impossibility to stay down in the hulls during passage. Now, is it true that flared painted hulls (so no internal panels) are basically not providing any kind of noise insulation?

[django37]

Many newer boats have never been weighed, and the displacement given is the designers optimistic hope

[jmschmidt]

I'm concerned with the new idea of moving the helm and all control lines to a flybridge or even popping the helm up above the top in a little copula. Both designs raise the center of effort of the mainsail and with all control lines running to a bank of clutches next to the driver he or she had better be quick locating the right clutch to dump the main when you come down off a wave and start to bury the lee hull. I think I'd wear a machete on my belt to dump them all.

[ozolli]

I am equally concerned about youtubers and their followers wanting helm stations protected behind 2 layers of windows and no view to the sails. Is it a boat or a car?

[rslifkin]

Originally Posted by ozolli

I am equally concerned about youtubers and their followers wanting helm stations protected behind 2 layers of windows and no view to the sails. Is it a boat or a car?

No view of the sails is a problem, but a protected helm can certainly make sailing in less than great weather much more pleasant. And much less tiring if in conditions that require a lot of attention. You'd be surprised how much being blasted by wind, spray, and sun can tire you out compared to operating a boat from a more protected helm.

[ozolli]

Originally Posted by rslifkin

No view of the sails is a problem, but a protected helm can certainly make sailing in less than great weather much more pleasant. And much less tiring if in conditions that require a lot of attention. You'd be surprised how much being blasted by wind, spray, and sun can tire you out compared to operating a boat from a more protected helm.

Well, I've been unprotected for more than 40 sailing years and still wanting to be there and not under a roof.