Are "Performance Cruising Catamarans" safe?

[Flobble]

There's nothing wrong with what is said in the video.

But some things which are important (to me, at least) are not said.

(1) The performance cruisers sail much better in light winds, when the capsize risks are very, very small. The heavyweights do not have this ability.

(2) The differences in 'capsize windspeed' can easily be solved by reefing. Then you get to the same stability figures as the heavyweights.

[smj]

Originally Posted by Flobble

There's nothing wrong with what is said in the video.



But some things which are important (to me, at least) are not said.



(1) The performance cruisers sail much better in light winds, when the capsize risks are very, very small. The heavyweights do not have this ability.



(2) The differences in 'capsize windspeed' can easily be solved by reefing. Then you get to the same stability figures as the heavyweights.

I agree, the beauty of the performance cat is the light wind sailing ability and the ability to sail in heavier winds with a greatly reduced sail area, still making good speed and reducing the stress’s on both the boats structure and the crew.
My only worry is the unexpected gust of strong wind that could possibly flip the performance cat. I think this scenario is the cause of most performance cats capsizing, and ad to that, a short handed crew.

[chrisr]

any sailing boat become dangerous if the crew use too much sail and performance cats still sail well AND safely when reefed

the heavyweight brigand never sail well

we are only just into the performance cat range and during a recent short ocean passage we were happy and safe with 2 reefs and abt 20% headsail...yet still doing 6-7kts in 18kts AWS (if it had been daylight i would have just had 1 reef and likely doing 8-9kts)

in other words, with a rig reduced to cope with any reasonably foreseeable gust / squall, a performance cat will still sail well

cheers,

[Factor]

YES - Yes they are. The bloke in the video from Antares is an absolute tosser.

[Lee Jerry]

I don't know where the safe vs unsafe (or dangerous) line is. And I didn't watch the video (too long right now). But...

A Ferrari is obviously and demonstrably less safe than a "regular" car or SUV. Even though the SUV is more likely to roll over. The Ferrari has more power and therefore just can get into situations where the others can't. Doing 150-180 mph is less safe than 100-120 mph, which is less safe than 80-90 mph. Even with superior brakes and steering, maneuvering at high speed is riskier than at lower speed. And when things go wrong at higher speeds the consequences are also higher. The higher speed also gives less reaction time (both for the vehicle and the driver). Things can go wrong from operator error, mechanical failure, or outside influences. Sure, you can drive a Ferrari at the same speed as the others, but how many people buy Ferraris to drive the speed limit? (Sure, there are some that just want to show off...) And you can't carry as much stuff in them.

The analogy transfers very well to sailing w.r.t. performance cruising catamarans.

But you also don't have to go to cars for the analogy. I think it is very similar for monohulls, between "classic bluewater cruisers" (like Oyster, Hallberg-Rassy, etc.) and more modern cruisers (like Beneteau, Jeanneau, etc.).

I'm not saying you shouldn't get a performance boat, but they are 'less' safe.

[catsketcher]

I'm not saying you shouldn't get a performance boat, but they are 'less' safe.

That is demonstrably untrue in a whole range of areas, and experience in catamarans will show this.

The problem with the video and statement above is that it assumes that all cats will have the same impact when capsized and equates all capsizes as the same risk when they are not. Heavier uncored cats with no inverted flotation will be more problematic when flipped, lighter cored cats with inverted flotation will have less safety risk from capsizing.

Also to think that safety is just related to capsize resistance is incorrect. Safety for some (like me) includes lower sheet loads due to less weight, smaller sails that produce lower loads, a gentler motion when going through waves due to weight being concentrated in the centre and accomodations being nearer the centre of gyration, the ability to claw your way off a lee shore under sail in over 35 knots, the ability to safely surf at close to 18 knots over a breaking NSW river bar, the ability to sail 80 miles to windward in daylight between coral anchorages, the ability for the boat to lope along at good speed under autopilot with little attention so I could keep a better eye on the kids, a simpler boat that allows me to have money left over for better safety equipment, and the ability for one person to sail the boat with no powered equipment. That is what makes a cat safe for me and that is what my cat can do.

That is some of my list. For me a heavier cat gets me closer to being unsafe because of the higher loads, the inability for me to singlehand within my effort limits with no electrics, taller accomodations, larger spaces inside without handholds and more. But others find these boats fine. But to say that a boat with the potential to do higher speeds is dangerous is plain wrong. Almost no one with a performance cat ever cruises it at full throttle, it is too hard, but you can still safely and easily cover lots of miles by letting the boat lope along. Just like you drive your car - who ever drives a car, even a nice powerful car at anything near its potential? The potential is there to be keep a higher average than an underpowered car and for towing and hills and sometimes, to let loose on the open roads (when no one is looking and conditions are just perfect).

Don't think that capsize resistance is the one metric to use to compare cats. it is much much more complex than this and everyone needs to work out what safety factors are important for them and decide accordingly. Yours will almost certainly be different from mine because we are all different humans.

cheers

Phil

[Lee Jerry]

Originally Posted by catsketcher

I'm not saying you shouldn't get a performance boat, but they are 'less' safe.

That is demonstrably untrue in a whole range of areas, and experience in catamarans will show this.

The problem with the video and statement above is that it assumes that all cats will have the same impact when capsized and equates all capsizes as the same risk when they are not. Heavier uncored cats with no inverted flotation will be more problematic when flipped, lighter cored cats with inverted flotation will have less safety risk from capsizing.

Also to think that safety is just related to capsize resistance is incorrect. Safety for some (like me) includes lower sheet loads due to less weight, smaller sails that produce lower loads, a gentler motion when going through waves due to weight being concentrated in the centre and accomodations being nearer the centre of gyration, the ability to claw your way off a lee shore under sail in over 35 knots, the ability to safely surf at close to 18 knots over a breaking NSW river bar, the ability to sail 80 miles to windward in daylight between coral anchorages, the ability for the boat to lope along at good speed under autopilot with little attention so I could keep a better eye on the kids, a simpler boat that allows me to have money left over for better safety equipment, and the ability for one person to sail the boat with no powered equipment. That is what makes a cat safe for me and that is what my cat can do.

That is some of my list. For me a heavier cat gets me closer to being unsafe because of the higher loads, the inability for me to singlehand within my effort limits with no electrics, taller accomodations, larger spaces inside without handholds and more. But others find these boats fine. But to say that a boat with the potential to do higher speeds is dangerous is plain wrong. Almost no one with a performance cat ever cruises it at full throttle, it is too hard, but you can still safely and easily cover lots of miles by letting the boat lope along. Just like you drive your car - who ever drives a car, even a nice powerful car at anything near its potential? The potential is there to be keep a higher average than an underpowered car and for towing and hills and sometimes, to let loose on the open roads (when no one is looking and conditions are just perfect).

Don't think that capsize resistance is the one metric to use to compare cats. it is much much more complex than this and everyone needs to work out what safety factors are important for them and decide accordingly. Yours will almost certainly be different from mine because we are all different humans.

cheers

Phil

I don't necessarily disagree with anything you said. But I'm not sure how effectively you've refuted the point.

First, I never said capsize resistance is the only metric of safety. I will say now it is the most important one (for multihulls). Almost all cats will stay afloat when inverted; their relative 'performance' while inverted is of little interest to me, it's better to avoid being inverted in the first place. Of course there are other aspects to safety. Like the ability to sail fast and better avoid bad weather. But maybe you don't quite make it out, or weather can be fickle and be different than the forecast, so you still have to be able to deal with bad weather. Another safety issue is collisions, whether with another boat, a reef or submerged container. Would you rather do that at a higher speed or a lower speed?

Where is the "performance cruising cat" limit? I would say Gunboat and HH for sure. But what about Catana and Outremere? Certainly not from five or so years ago, maybe some models today. I think it takes more than a centerboard.

I don't know your boat, I'll assume it's a "performance cat," but if the "11.6" refers to the LOA in meters, a bunch of what you call safety may not be due to the performance scale of the boat but rather the size. A 38' boat has relatively small sails and does not need powered winches, even a cruising cat or cruising monohull. In fact, a lot of what you said is more 'small vs large' as opposed to 'cruisy vs performance.' It's also arguable whether much of your preferences that you call safety aren't more appropriately called lifestyle choices (not that there's anything wrong with that ).

A couple other small points. Performance almost always costs more money - carbon is more expensive than glass, for example. Obviously you can save weight and money by eliminating equipment, but then you're not really comparing apples to apples. Many people would drive cars closer to their limit (the car's, probably past the driver's) if they weren't limited by law.

And yes, everyone can decide for themselves what they want in a boat. No matter how wrong they are.

[Chotu]

A quick point about collisions.

damage to a boat is a function of the hull's ability to absorb impact without rupture and the momentum of the boat. Not the speed.

My boat is significantly better than most in collisions because it doesn’t weigh anything and it’s made of foam. Therefore, it does not have much momentum and it absorbs impacts pretty well.

unfortunately I know all about this thanks to hurricanes. I have a ton of cosmetic damage from hurricanes hitting this boat. And I don’t mean little ones. We’re talking category four. it smashed up against the seawall with a bunch of other boats when the "mooring field" let go. several of the other boats sank in that crowd. But because mine doesn’t have much momentum, it didn’t really even get damaged too much. certainly nothing structural.

It’s a very important point to remember. You can’t picture the same boat you have when you picture a fast Catamaran. It’s not the same thing at all. It’s completely different. many assumptions and rules do not apply.

[double u]

monohull stabiity curve at abt 9:10 is BS

[Lee Jerry]

Originally Posted by Chotu

A quick point about collisions.

damage to a boat is a function of the hull's ability to absorb impact without rupture and the momentum of the boat. Not the speed.

My boat is significantly better than most in collisions because it doesn’t weigh anything and it’s made of foam. Therefore, it does not have much momentum and it absorbs impacts pretty well.

unfortunately I know all about this thanks to hurricanes. I have a ton of cosmetic damage from hurricanes hitting this boat. And I don’t mean little ones. We’re talking category four. it smashed up against the seawall with a bunch of other boats when the "mooring field" let go. several of the other boats sank in that crowd. But because mine doesn’t have much momentum, it didn’t really even get damaged too much. certainly nothing structural.

It’s a very important point to remember. You can’t picture the same boat you have when you picture a fast Catamaran. It’s not the same thing at all. It’s completely different. many assumptions and rules do not apply.

You can't say it's a "function of ... the momentum of the boat. Not the speed." Momentum IS a function of speed: momentum = mass x velocity (velocity is the same as speed for our purposes). The faster a boat is going, the more momentum it has, the more momentum has to be slowed or stopped.

Yes, how the hull reacts to the impact is one aspect. And it'll vary considerably depending on the nature of that impact. But banging into a dock is not really the type of collision that we're talking about. It's more about sailing at speed and coming to a rapid stop (from grounding, hitting container, or whatever).

So another aspect of this collision is: what happens to the person standing in the boat? Do you think they'll fare better hitting the bulkhead at 8 kt or 15 kt?

What about the rig? Which is more likely to survive: a large powered up rig going from 15 kt to zero in short order; or a smaller, less powerful, stout rig going from 8 kt to zero?

I haven't had the pleasure of sailing a large performance catamaran (only beach cats, Hobie trifoiler), but physics still applies.

[Chotu]

Originally Posted by Lee Jerry

You can't say it's a "function of ... the momentum of the boat. Not the speed." Momentum IS a function of speed: momentum = mass x velocity (velocity is the same as speed for our purposes). The faster a boat is going, the more momentum it has, the more momentum has to be slowed or stopped.

Yes, how the hull reacts to the impact is one aspect. And it'll vary considerably depending on the nature of that impact. But banging into a dock is not really the type of collision that we're talking about. It's more about sailing at speed and coming to a rapid stop (from grounding, hitting container, or whatever).

So another aspect of this collision is: what happens to the person standing in the boat? Do you think they'll fare better hitting the bulkhead at 8 kt or 15 kt?

What about the rig? Which is more likely to survive: a large powered up rig going from 15 kt to zero in short order; or a smaller, less powerful, stout rig going from 8 kt to zero?

I haven't had the pleasure of sailing a large performance catamaran (only beach cats, Hobie trifoiler), but physics still applies.

Could you please define momentum for me again? I had no idea. Lol. What is v-e-l-o-c-i-t-y?

I love how you just ignore 1/2 of the equation. your post only talks about the velocity. It doesn’t talk about the mass in combination with velocity when both are equally weighted in the Newtonian equation for momentum.

"The faster a boat is going the more momentum it has." Only holds true if it’s the same mass as the slower boat.
It's not. Hylas 48=44,000lbs. My 50ft cat=16,000lbs. Given the same velocity, my boat has approximately 1/3 the momentum yours does on impact AND is made of a material that better absorbs impact without rupture. (Plus has 2 forward watertight crash bulkheads and sacrificial bows)

Or put another way, your boat can be doing 8 kn and have an impact while mine can be doing 24 kn and have an impact and we both have the same momentum. This comes straight out of the momentum equation you posted. thank you for proving my point empirically.


speaking to your rigging question for a moment.

do you think that a boat with a rig that can handle the forces of a boat that doesn't heel has the same size rigging as your boat? Lol Our rigs are massively more robust. They have to be because we don't heel.

Here's a thought experiment for you since you can’t picture it with boats.

throw a model airplane at a brick wall. Now throw a paper airplane at the same brick wall. What happens?

Physics definitely applies. I agree with you. I think you just forgot to apply it.

[Lee Jerry]

Originally Posted by Chotu

Here's a thought experiment for you since you can’t picture it with boats.

throw a model car at a brick wall. Now throw a paper airplane at the same brick wall. What happens?

I get it just fine.

Throw a person at a wall at 8 kt. Throw a person at a wall 15kt. What happens?

Velocity is speed with direction; it's a vector quantity.


Ok, you keep editing your post and I'll keep editing mine.

"A boat" means the same boat at two different speeds.

Shall we talk about kinetic energy?

Or would you rather go back to the cars? You know they test those by actually running them into your "brick" wall? I'm pretty sure a small car going fast does worse than a large one going slower.


OK, changed my mind - I'm not going to keep editing mine. Last one...
If you're referring to my boat, it's a 46 and has a lightship more like 28,000 lb.
Damage would depend on the nature of the impact. Do you have centerboards?
But the point is you're supposed to be going faster...

[Lee Jerry]

Originally Posted by double u

monohull stabiity curve at abt 9:10 is BS

Why would you say that? It's a plausible curve.

[Chrisatlantic]

If we make the assumption that when it’s windy out we’re going to reef, the more sail area relative to stability that performance cats have is offset by the reefed sailplan, enabling the performance cat to be sailed with similar safety to the ‘cruising’ cat.

And fundamentally that is the pact that owners of performance cats have to make to operate safely. Want to sit inside and eat dinner and not pay attention to the weather? Reef first. Want to leave the least experienced person alone on watch on an unsettled night? Double reef. Want to go to sleep while single handing? You’ve taken on all kinds of risk issues, I’m sure you’d never watch the Antares video anyway.

Know your boat, know how to sail and are willing to pay attention to what’s going on? Enjoy your performance cat! Throttle back when appropriate and safety is maintained.

For people who want their boat to be safe regardless of what operational decisions they make, they should not buy a performance cat. The Antares video is so Chicken Little “sky is falling” — I find it ridiculous that essentially the argument is being made that sail area to stability is an absolute when in fact it is the operator that determines the sail area at any given time and the amount they choose to utilize is what is going to be relevant to whether their boat is at risk of capsize or not.

[fxykty]

I’ve been restraining myself, but the BS being spouted by posters who have no idea other than stories is really irritating. I absolutely don’t care what type of boat you prefer or have yourself and I don’t write to proselytise anything either. I do write to set the record straight.

We have an older cat (2003) with solid glass hulls (about half an inch thick at the turn of the bilge) and foam-cored decks, cabin, bulkheads and furniture. There is no carbon, kevlar or anything else high tech in the build, yet it is 40% lighter than the new equivalent design from the same manufacturer.

It is 16.4m/54’ long and weighs 7550kg/16,600# empty and 11,500kg/25,350# loaded for cruising. We have 122sqm/1313sqft of white sails. Our mast is 19m/62.5’ high. We have no electric winches and don’t need them. If we’re particularly lazy we use the anchor windlass to hoist the main halyard. The boat is easily single handed.

Not long ago we were parked beside a new Leopard 50. Length 15.4m/50.5’, weighs 19,000kg/41,880# empty and 26,000kg/57,320# loaded. White sails 153.5sqm/1654sqft and a 23.5m/77’ mast height. It has electric winches throughout.

By the time we have 20kts TWS we can be double reefed mainsail and 2/3 of our jib and still sail 8 knots upwind or 10-12 knots reaching and downwind. The Leopard will still have full sails and will struggle to make 8 knots at 5* wider and 9kts reaching/downwind.

Which boat do you think is safer?