New design performance catamarans are heavy - why is that?

[fxykty]

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.

The vast majority of the time the autopilot is steering, so why is a protected helm so important? This is one of the weird design trends that charter catamarans seem to have made mainstream - it used to be that only high latitude boats had dry steering and control stations.

In our case with an older design, our boat is not operated from the helm station as lines, clutches and winches are distributed around the cockpit and the base of the mast. Yes, when it rains we wear wet weather gear and/or get wet - shock, horror. When it’s sunny we use sunscreen and wear hats! I guess we’re weird.

[zstine]

A low prismatic coefficient (<0.55) is easily driven and optimized for speeds below displacement hull speed. It will exhibit a significant drag hump compared to a high prismatic (>0.57) which has fuller ends, flat stern sections and maybe some transom submergence, will have higher lift and is optimized for speeds at or above hull speed. For an older Outremer 55, with a low prismatic, light weight, this boat will perform well in light air but may hit a wall, sort of at, ~10-11 knts, where the drag hump would be difficult for the less powerful rig to push through. The finer end sections will also result in a likelihood to pitch more. While the higher prismatic modern boat with a powerful rig may struggle to keep up with the Outremer in light air, it has higher lift hulls to reduce the drag hump and the powerful rig can push past the hump. This is perhaps why you see modern polars with speeds over 20knts while you don't with older lighter boats. Pitching would be less sever with fuller stern section as well, and you can carry more load. So, yes the modern design is more expensive and perhaps not as easy to drive in light air and requires bigger equipment, but it can 'cruise' at higher speed with more payload when the winds pick up enough to drive the hull.. maybe 12-15knts.? Perhaps the older Outremer 55 is more equal to a modern 50' foot boat. Modern design gives you a little more for the length.

[Training Wheels]

Originally Posted by ozolli

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

I’ll second that!

[rslifkin]

Originally Posted by fxykty

The vast majority of the time the autopilot is steering, so why is a protected helm so important? This is one of the weird design trends that charter catamarans seem to have made mainstream - it used to be that only high latitude boats had dry steering and control stations.

In our case with an older design, our boat is not operated from the helm station as lines, clutches and winches are distributed around the cockpit and the base of the mast. Yes, when it rains we wear wet weather gear and/or get wet - shock, horror. When it’s sunny we use sunscreen and wear hats! I guess we’re weird.

When I think "helm", I'm thinking of the area you'd access most of the controls from, not just steering. If you've got most of the sail controls (or at least the frequently used ones) led to 1 area then weather protection becomes much easier.



Comparing running my powerboat as well as various sailboats, I've found the less protected the helm area is, the more tired I feel after a few hours. Being in the sun and wind isn't necessarily unpleasant at the time, but after a few hours when stopping, I find I'm a lot more tired than if there's some shade overhead and at least something to break the wind. And of course, on those days where it's raining, but otherwise appropriate to travel, it's nice not to be stuck in foulies (especially if it's hot out).



Thinking about it, if you're going to have a cabin structure with a forward view on a cat, or a layout that leaves you with a dodger and bimini, it's not like there's much windage penalty for putting the helm in an enclosed space. The keys to doing it right are being able to open things up enough for ventilation when desired, and making sure you can still see what the sails are doing, etc. So a few well placed hatches overhead are necessary.

[billgewater]

Well, I'm pleased all that has been resolved. Oh?

[catsketcher]

Originally Posted by zstine

This is perhaps why you see modern polars with speeds over 20knts while you don't with older lighter boats. Pitching would be less sever with fuller stern section as well, and you can carry more load. So, yes the modern design is more expensive and perhaps not as easy to drive in light air and requires bigger equipment, but it can 'cruise' at higher speed with more payload when the winds pick up enough to drive the hull.. maybe 12-15knts.? Perhaps the older Outremer 55 is more equal to a modern 50' foot boat. Modern design gives you a little more for the length.

I am not sure prismatics have changed much since the 1990s. Certainly, cats from the 60s and 70s were much finer but in Australia cats like Bagatelle showed the way for high prismatics in the early 80s, so we were up to increasing bouyancy in the ends about 40 years ago.

As for going fast at high speeds - maybe that is the thing. I certainly don't get a lot of time at high speeds, even though my boat can achieve high speeds. I spend a lot of time throttling back as it gets bumpy if we go too fast. More weight could help here, by reducing accelerations at higher speeds.

But my contention is that high performance cats are not that useful because they do 20 knots - I don't want to do 20 knots. What I want is to do 8 knots in 10 knots of breeze or 10 knots in 13 knots of breeze. Because that is where we make the biggest gains.

A focus on the top end of polars does not take into account the real work use of cruising cats. It is the high potential at low speeds that makes a huge difference to the sailability of a boat - 2 knots of top end potential - from 18 to 20 knots boatspeed is pretty much worthless as it incredibly rare to get the conditions to allow someone to CRUISE at this speed. Very few sailors want to - things happen too fast, the gear is too stressed and it is hard to hang on.

But it is very common to want to to do 8 knots when the water is flat and blowing 8 knots and you sail in magic carpet mode - gliding along like a train with the Code 0 up when others are motoring. I would trade 4 knots top speed to get my boat doing 1 knot more in 7-15 knots windspeed. I actually said that to my designer when I asked him to design me my cat "I don't care how fast she goes - I just want her to get to 8 knots really quickly". ( I got greedy quickly and like 9 and even 12 knots too and 15 is fun.) Lighter winds are where the vast majority of my time asking the boat to go its fastest occurs. So don't judge a performance cruiser by its top end polars - judge them by the light-medium air polars. The heavy ones may have a slight edge in the heavy breezes at the highest of speeds (that no one wants to do) but the ones orientated towards lighter winds will be able to utilise their full potential much more often and sail past the cats with higher top end specs much more of the time.

[Chotu]

Catsketcher’s last post is worth reading twice.

This is exactly what we are after with high-performance catamarans.

[smj]

Originally Posted by Chotu

Catsketcher’s last post is worth reading twice.

This is exactly what we are after with high-performance catamarans.

Exactly, the ability to sail in light winds rather than motor.

[Chotu]

Originally Posted by smj

Exactly, the ability to sail in light winds rather than motor.

Exactly. That’s why I decided to build one in the first place.

I had spent decades on heavy monos wishing for more wind. I rarely have a situation that I am wishing there was less wind. At least 90% of the time I had wished for more wind because the boat wouldn’t move.

The dream was to be able to have something that would actually sail well and a decent waterline length (and form stability) to make it comfortable at sea and at anchor.

Never really subscribed to the fancy luxurious stuff. More about practicality.

[wingssail]

Originally Posted by 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.

I've seen quite a few of these boats in recent years. I agree that the mainsail COE way up there and the boats to me look ungainly. But I've never seen one with the sails up.

The designers of those boats with the helm up above the top in a little copula are not interested in how it sails or if it is dangerous sailing in a big blow; that's not the use case for these boats. They are meant to be motored with pampered VIP's strewn around looking either relaxed or bored.

Meanwhile, in a fresh headwind, the exposed helm's person is getting a lot of wind. By this time the guests or family have retired to the cabin and are discussing next week's cocktail party or where they are going to dinner when they get to port.

This is not your gunboat crowd and not the topic of the OP's query.

[wingssail]

Originally Posted by ozolli

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

I never trust a sailor who is happy sailing a boat where he has no view of the sails and who never needs to feel the wind in his face.

[Joli]

Originally Posted by wingssail

I've seen quite a few of these boats in recent years. I agree that the mainsail COE way up there and the boats to me look ungainly. But I've never seen one with the sails up.

The designers of those boats with the helm up above the top in a little copula are not interested in how it sails or if it is dangerous sailing in a big blow; that's not the use case for these boats. The are meant to be motored with pampered VIP's strewn around looking either relaxed or bored.

Meanwhile, in a fresh headwind, the exposed helm's person is getting a lot of wind. By this time the guests or family have retired to the cabin and are discussing next week's cocktail party or where they are going to dinner when they get to port.

This is not your gunboat crowd and not the topic of the OP's query.

Looking around the harbor (Bequia) about half the boats are Lagoons, FP's or Leapord's with the raised steering station. They all seem to sail everywhere we do. No Gunboats or HH's here.

[smj]

Originally Posted by wingssail

I've seen quite a few of these boats in recent years. I agree that the mainsail COE way up there and the boats to me look ungainly. But I've never seen one with the sails up.

The designers of those boats with the helm up above the top in a little copula are not interested in how it sails or if it is dangerous sailing in a big blow; that's not the use case for these boats. They are meant to be motored with pampered VIP's strewn around looking either relaxed or bored.

Meanwhile, in a fresh headwind, the exposed helm's person is getting a lot of wind. By this time the guests or family have retired to the cabin and are discussing next week's cocktail party or where they are going to dinner when they get to port.

This is not your gunboat crowd and not the topic of the OP's query.

Yeah, catamaran Impi never sails anywhere [emoji23]

https://youtu.be/Bp6oTLsx-NI
I’m not a fan of the fly bridge cat but to state they never sail is a ridiculous statement.

[wingssail]

Originally Posted by Chotu

Catsketcher’s last post is worth reading twice.

This is exactly what we are after with high-performance catamarans.

Yes, Catsketcher's post is right on:

Originally Posted by catsketcher

...The heavy ones may have a slight edge in the heavy breezes at the highest of speeds (that no one wants to do) but the ones orientated towards lighter winds will be able to utilise their full potential much more often and sail past the cats with higher top end specs much more of the time...

that is an important consideration for a boat for active sailors, however, the market for that boat is small. Other than cartsketcher and kxykty there aren't to many other active sailors out there compared to the condomaran crowd who's main consideration is how closely it matches the luxury home they have ashore, and will the vase remain upright on the counter-top when sailing and if they never sail anywhere, they're fine with that.

And who wants lines and winches and other sailing hardware cluttering up the lounging areas or the marble countertops.

This is why the modern cats are maybe not the best performers.

[Sos]

Watch Parley Revival's latest couple of videos about a local race, that they instigated a few years ago,and entered.
As much as many won't agree they were sailing well and done quite well. Not my type of boat but they can sail even if they don't look right. Not what this thread is about mind!