Another stability question

[Tsalta]

Hi,

First post. Pls be gentle.

I’ve only ever sailed mono’s but the only way I’ll ever get the boss on board a boat long term is on a cat. Space, comfort and all that non essential stuff.

Anyway, last week helming on a Farr 40ft in a nice steady 15kts close hauled heading for the top mark, we encountered a nice 30 degree wind shift and gust up to 25-30 kts.

My question is regarding how do cats handle this? What if you have the AP on and are inside making a cup of tea and don’t see the bullet?

From what I have read, cats are reef by the numbers so potentially there could be too much sail up. Am I going to end up inverted?

Cheers

[chrisr]

short answer : it very much depends on the boat. a light weight racing cat needs constant attention

a relatively heavy cruising cat (like ours) not so much

in a gust that would have a mono heel over to de-power, the cat should (ideally) slide sideways. this is why cats with centerboards require more attention than a cat with mini-keels, but in either case (in fact in all boats) you need to ensure the rig set up is correct for the conditions

most cruising cats will not invert in flat water by wind alone, but plenty of the more twitchy lightweight boats (especially if centerboard) can...and will !

as for 'reefing by numbers' : this may suit some folk who don't know better. we prefer to make our own decisions based upon the conditions and our experience.

cheers,

[Chotu]

It's all about dumping the mainsheet if caught with too much sail up.

This is a concern of mine as well.

Does anyone know of a reasonable "fuse" or "circuit breaker" for this purpose?

One might be far from the helm and sheet controls when a sudden gust hits, traveling on autopilot. In this case a more automatic system, based on the heeling angle of the boat might be best. Something that releases on a certain number of degrees of heel or certain tension on the sheet.

[Tsalta]

When it comes to cats, I am definitely in the “don’t know better” group. I think the biggest one I have sailed was a hobie 16.

Although I have always been a mono dude, I can 100% see the appeal of a cat. I just need to get my head around how to sail them safely. The lack of ability for the boat to spill power is something I am struggling with.

I need to get some sea time on one.

Cheers

[rslifkin]

Originally Posted by Chotu

It's all about dumping the mainsheet if caught with too much sail up.

This is a concern of mine as well.

Does anyone know of a reasonable "fuse" or "circuit breaker" for this purpose?

One might be far from the helm and sheet controls when a sudden gust hits, traveling on autopilot. In this case a more automatic system, based on the heeling angle of the boat might be best. Something that releases on a certain number of degrees of heel or certain tension on the sheet.

It wouldn't be automatic, but you could use an electric mainsheet winch with remote control and keep the remote with you when elsewhere on the boat. If it's all rigged right and the winch is fast enough, that would serve as a "dump" button.

[Dpackie]

Could the auto helm be integrated with the wind instruments to react by rounding up if wind speed increased by a preset percentage or predetermined wind speed? If not, new product development and I only want 5% of gross annual sales. TM.

[donradcliffe]

The owner's manual for a cat should give you the 'numbers' for a safe sail combination vs windspeed in sheltered waters. Look at ISO 12217-2 so see how the 'safe' numbers are derived, and you will see there is at least a 30% windspeed safety factor involved. If you are daysailing and have someone minding the mainsheet, you can push the boat a lot harder. If you are doublehanding at night, you will want to reef down a bit more than recommended, especially in large seas and squally winds. I believe that most manuals don't go beyond about 50-55 knots but cruising cats are probably good for 80=90 barepoled.

[Rennsail]

Originally Posted by donradcliffe

but cruising cats are probably good for 80=90 barepoled.

YIKES! But only downwind and with a drogue.. for reference as to what it may be like, see this video. These two actually seem to be enjoying it. My Admiral would be simultaneously cursing me, the weather, the boat...but mostly me.

[barnakiel]

A racing one will capsize if locked in.


But a cruising one will just get loaded so that you know you must go out and do something to it.


No worries. Cruising cats are nothing like a Farr40 or a Nacra.



barnakiel

[Chotu]

Originally Posted by Dpackie

Could the auto helm be integrated with the wind instruments to react by rounding up if wind speed increased by a preset percentage or predetermined wind speed? If not, new product development and I only want 5% of gross annual sales. TM.

Nope. That's the wrong technique on a fast cat. Falling off is the right response. Yet still, way scary compared to dumping the main.

[Chotu]

Originally Posted by barnakiel

A racing one will capsize if locked in.


But a cruising one will just get loaded so that you know you must go out and do something to it.


No worries. Cruising cats are nothing like a Farr40 or a Nacra.



barnakiel

Unless they're my boat.

[thinwater]

Originally Posted by chrisr

...in a gust that would have a mono heel over to de-power, the cat should (ideally) slide sideways....

Nope. Any cat that would slide sideways before flying a hull won't sail to weather for beans. I wouldn't want such a boat.


---


Obviously, the windspeed at which capsize is a factor depends on boat size and how much canvass she carries. Slow cats are under canvassed for safety... and generally miserable sailing.

[thinwater]

Originally Posted by Chotu

Nope. That's the wrong technique on a fast cat. Falling off is the right response. Yet still, way scary compared to dumping the main.

Deep off the wind, yes. Hard on the wind, weather, feather and ease. In between you have choices. You know this.

[Dpackie]

Originally Posted by thinwater

Deep off the wind, yes. Hard on the wind, weather, feather and ease. In between you have choices. You know this.

I have never sailed a cat so I don't know squat. That said, I have sailed enough to know the basic physics. If you were reaching in high winds wouldn't falling off lead to a very real danger of jibbing, considering the seas and off wind rolling that occurs? I also don't understand how this de-powers more effectively then heading up, other then slightly lessening apparent wind speed. Certainly not doubting the expertise here, genuine curiosity, if you have a moment to explain. Does a cat not round up on it's own when overpowered?

[Chotu]

Originally Posted by thinwater

Deep off the wind, yes. Hard on the wind, weather, feather and ease. In between you have choices. You know this.

Ok, ok. It varies. You're right. I was thinking of a limited situation.


I wonder how much only using the windward dagger board can help in a gust capsize situation when close hauled.