How many cats have flipped ?

[44'cruisingcat]

Nice thing about an easily driven boat: you carry as much sail as you need, not as much as you can.

https://youtu.be/o4PoObnQrpc

Wind was 15-18 kts. We could have carried full main and jib with ease. Sailing conservatively I'd normally have a reef in. But I noticed the first reef line was getting a bit frayed, so tucked two reefs in. And still sailed the 55 miles in 5 hours.

[jmh2002]

Originally Posted by 44'cruisingcat

Nice thing about an easily driven boat: you carry as much sail as you need, not as much as you can.

^^^ Exactly.

[Dockhead]

Originally Posted by 44'cruisingcat

Nice thing about an easily driven boat: you carry as much sail as you need, not as much as you can.. . .

Yes!! That is the very heart of the matter. And it is not specific to catamarans, even if it is easier to arrange easy-drivenness in boats without ballast. In monos, you need waterline length, fineness, and lightness to achieve this, and that was the key design value for Dashew's Sundeer hull form.

[Paul Howard]

Yes, that is the same boat, Walter Greene Even Keel design, built by the Damien Mclaughlin Corp., RAIN, now at the Toronto Multihull Cruising Club.
Paul H.

[smj]

Originally Posted by Paul Howard

Yes, that is the same boat, Walter Greene Even Keel design, built by the Damien Mclaughlin Corp., RAIN, now at the Toronto Multihull Cruising Club.
Paul H.

We looked at her when she was for sale. Really pretty cat and I bet she sails really well.

[tomfl]

Originally Posted by 44'cruisingcat

Nice thing about an easily driven boat: you carry as much sail as you need, not as much as you can.

https://youtu.be/o4PoObnQrpc

Wind was 15-18 kts. We could have carried full main and jib with ease. Sailing conservatively I'd normally have a reef in. But I noticed the first reef line was getting a bit frayed, so tucked two reefs in. And still sailed the 55 miles in 5 hours.

Saw what seemed to be the wind speed at 19.9, maybe AWS not TWS. But you could go faster if you were not trailing a fishing line off the boat.

[fxykty]

Originally Posted by David M

I don't think that statistic exists. My gut feeling is that catamarans capsize more often per cruising mile. I can't prove that though.

All one can really say is that at a 90 degree angle of inclination that a catamaran is unlikely to right itself but a monohull is likely to right itself as long as there was a minimal amount of water ingress into the cabin. Both types of vessels have very different righting moment curves. This would only apply to ocean swell that is not severe. Under severe conditions where you have swells rolling I would imagine the chance of rolling is about equal given the same angle of inclination into the swell.

I know this will stir up controversy but I think monohulls overall have a bit of an advantage in severe wind and ocean swell conditions.

On the other side of the debate, catamarans have a greater initial righting moment and less beam per hull providing a speed advantage allowing them to dodge low pressure areas more readily. If you have the ability to reduce the chance of getting into a bad situation in the first place then that is a distinct advantage.

I've bolded your text where you are incorrect. The force of buoyancy on a hull (or on two hulls as in a catamaran) on a given wave angle is at right angles to the water surface. The force of gravity can be split into two vectors - one vector at right angles to the water surface (directly opposing the buoyancy force) and the other vector parallel to the water surface. The latter vector will push the hull down the wave face and increases as the angle steepens (as the total gravity force must equal the total buoyancy force).

The angle of a catamaran on a wave does not materially affect overall stability as the sideways gravity vector causes the catamaran to skid down the wave (especially if the catamaran doesn't have mini keels). This also increases the buoyancy force on the leeward hull, increasing righting moment. Unlike a monohull, whose keel tends to trip it into a roll rather than skid.

Of course, in extreme conditions neither catamarans nor monohulls want to be sideways to the waves. Hence the use of parachute anchors and drogues to stay aligned with the predominant wave direction. Bummer about the rogue waves at off angles.

[44'cruisingcat]

Originally Posted by fxykty

I've bolded your text where you are incorrect.

A little of it anyway.

[jmschmidt]

Originally Posted by 44'cruisingcat

An indication of how infrequently cruising cats capsize is in the thread about what it's like in an upturned cat. Nobody on this forum (of how many members?) could say.

That could be that those that have are no longer with us.

My debate and logic professor would call the a "fallacy of the major premise".

[44'cruisingcat]

Originally Posted by jmschmidt

That could be that those that have are no longer with us.

My debate and logic professor would call the a "fallacy of the major premise".

And I would call that a load of crap.

[MartinR]

I do not think we have any statistics! So no answer to the question is possible.

[Bullshooter]

Can someone explain this statement from page 5:

"you can take the tail, where the stripper takes the line out of the self tailing mechanism, and reverse the direction so that you can very quickly get it out of the self tailer, even from a distance."

I am having trouble picturing what is meant by this. (A photo would help)

Thank you

[category4jay]

Originally Posted by 44'cruisingcat

Actually cat's tip over far less frequently.


http://www.multihulldynamics.com/new...p?articleID=11

That’s a good read! Thanks.

[KP44]

Originally Posted by Fore and Aft

I know of three that have flipped. The first was a 40’ foot Wharram in Wellington Harbour. The guy had way to much sail up and when he left the lee of our yard the first few gusts just flipped him.
The second was a 40’ cat on the Wide Bay Bar, bad timing I believe and he got flipped crossing at night.
The third cat was a 32’ Fast Back, racing in Moreton bay. Flipped while pushing her to hard.
Cheers

I remember the 40' Cat, RAMTHA, in the Queen's Birthday Storm. Several boats had problems. And it appears the Catamaran's crew abandoned ship. Ramtha was found intact after the storm but the life-raft and crew were never found.
Even without a crew to guide her, the Cat came through the storm.

[smj]

[QUOTE=KP44;2906197]I remember the 40' Cat, RAMTHA, in the Queen's Birthday Storm. Several boats had problems. And it appears the Catamaran's crew abandoned ship. Ramtha was found intact after the storm but the life-raft and crew were never found.

Even without a crew to guide her, the Cat came through the storm.[/
Ramtha’s crew got pulled of the cat by a ship and survived to sail Ramtha again.