Cat Capsize Lake Macquarie

[arsenelupiga]

Originally Posted by 44'cruisingcat

Probably much that you believe isn't true.

this keel attachment looks rather toyish... I suspect they additionally strengthened attachment with sikaflex.

[Jim Cate]

Originally Posted by chrisr

someone on a leadmine was telling that the channel has been dredged recently. he draws 2.2m and had a metre clear.

when are you coming to visit ?

cheers,

Chris, I've heard that SO many times, often shortly before running aground at the dropoff. We've followed a guide boat and run aground. We've been told it had just been dredged to 3 meters and run aground. I no longer will believe any such stories without some real proof... and even then, the sands shift so rapidly in the dropoff area that day to day changes are possible.

I'm gonna be a hard sell!

Jim

[chrisr]

Originally Posted by Jim Cate

Chris, I've heard that SO many times, often shortly before running aground at the dropoff. We've followed a guide boat and run aground. We've been told it had just been dredged to 3 meters and run aground. I no longer will believe any such stories without some real proof... and even then, the sands shift so rapidly in the dropoff area that day to day changes are possible.

I'm gonna be a hard sell!

Jim

haha...fair enough...can't say i blame you

[GILow]

Originally Posted by Jim Cate

Chris, I've heard that SO many times, often shortly before running aground at the dropoff. We've followed a guide boat and run aground. We've been told it had just been dredged to 3 meters and run aground. I no longer will believe any such stories without some real proof... and even then, the sands shift so rapidly in the dropoff area that day to day changes are possible.



I'm gonna be a hard sell!



Jim

Don’t worry Jim, I’ll check it out for you. I only draw 1.7 meters and I recently tested my shallow water navigation methodology to the extreme with no more than a bruised ego.

[Factor]

Originally Posted by ErnestV

Monos depower with every degree they tilt, so it should be near to impossible to lay a mono flat by wind power alone..

And yet I have seen it happen many many many times

[Jim Cate]

Originally Posted by Factor

And yet I have seen it happen many many many times

Maybe with a kite flying, because it may not spill the wind when the boat heels. But when flying plain sails only, unless the wind has a big vertical component getting truly mast in the water from wind alone is pretty unlikely.

There are places in the world where gusts do indeed have vertical components. When I used to race in SF Bay years ago, there was a race mark in a place known as Yellow Bluff, and there were some cliff-like structures there that seemed to generate such gusts. I had a couple of mast in the water knockdowns in my Catalina 22 as a result... but nowhere else in the bay, despite stronger winds in general.

So I dunno what you observed or thought you observed, but what you describe sure does not jibe with my observations over many years and miles.

Jim

[smj]

Originally Posted by Jim Cate

Maybe with a kite flying, because it may not spill the wind when the boat heels. But when flying plain sails only, unless the wind has a big vertical component getting truly mast in the water from wind alone is pretty unlikely.



There are places in the world where gusts do indeed have vertical components. When I used to race in SF Bay years ago, there was a race mark in a place known as Yellow Bluff, and there were some cliff-like structures there that seemed to generate such gusts. I had a couple of mast in the water knockdowns in my Catalina 22 as a result... but nowhere else in the bay, despite stronger winds in general.



So I dunno what you observed or thought you observed, but what you describe sure does not jibe with my observations over many years and miles.



Jim

I’ve seen it happen with monos, bare poles at anchor. I’m sure it’s more common with sail up?

[Jim Cate]

Originally Posted by smj

I’ve seen it happen with monos, bare poles at anchor. I’m sure it’s more common with sail up?

Astonishing. Details?

Jim

[Uncle Bob]

Originally Posted by Jim Cate

Astonishing. Details?

Jim

I too would love to hear the details.

[GILow]

Originally Posted by smj

I’ve seen it happen with monos, bare poles at anchor. I’m sure it’s more common with sail up?

Yeah, it happens. To Mirror dinghies.

[smj]

Originally Posted by Jim Cate

Astonishing. Details?



Jim

At anchor when hit with initial 90-100 kts gust

[Jim Cate]

Originally Posted by smj

At anchor when hit with initial 90-100 kts gust

I was hoping for something a bit more specific here, with things like type and size of boat, sea state, location, preceding conditions, AWA of gust, duration of gust and of the knockdown, where the wind speed measurement was made relative to the knockdownd... you know, useful info that would tell us something about how such an event could possibly occur.

There was recently a short and kinda vague video posted here of a tornado-like event somewhere in NZ where a catamaran was bodily lifted and thrown off of the hard, and in the background it appeared that a moored super yacht was knocked nearly flat... but not mast in the water, quite. A very impressive event to be sure, but hardly supports the "I've see it many many times" kinda statements... it was extraordinary to be sure.

I'm not saying it can't happen... I've seen a fair number of perhaps 60 degree "knockdowns" and a couple of wet mast events, but they involved race boats broaching with big kites up, and wave action was certainly involved in those.

Skepticism is generated in my mind when considering that as a ballasted monohull yacht approaches 90 degrees of heel it also approaches its maximum righting moment, just w hen the heeling force from the sails approaches zero (assuming normal horizontal wind flow).

Jim

[GBR134]

I’ve seen a 21ft mono capsize on its mooring just off the end of Brancaster Staithe Hard in a Gale if wind blowing against a string incoming tide. The boat was swinging wildly until eventually it went over and stayed over.

Once it had capsized it was even more obvious that this was a center board cruiser with the keep fully retracted!

[smj]

Originally Posted by Jim Cate

I was hoping for something a bit more specific here, with things like type and size of boat, sea state, location, preceding conditions, AWA of gust, duration of gust and of the knockdown, where the wind speed measurement was made relative to the knockdownd... you know, useful info that would tell us something about how such an event could possibly occur.



There was recently a short and kinda vague video posted here of a tornado-like event somewhere in NZ where a catamaran was bodily lifted and thrown off of the hard, and in the background it appeared that a moored super yacht was knocked nearly flat... but not mast in the water, quite. A very impressive event to be sure, but hardly supports the "I've see it many many times" kinda statements... it was extraordinary to be sure.



I'm not saying it can't happen... I've seen a fair number of perhaps 60 degree "knockdowns" and a couple of wet mast events, but they involved race boats broaching with big kites up, and wave action was certainly involved in those.



Skepticism is generated in my mind when considering that as a ballasted monohull yacht approaches 90 degrees of heel it also approaches its maximum righting moment, just w hen the heeling force from the sails approaches zero (assuming normal horizontal wind flow).



Jim

This is the storm https://www.tcpalm.com/story/weather...ago/315723002/
It was almost 30 years ago so my memory has slightly faded but it was on our first cruise on our first catamaran. I’d come from a monohull background and was amazed at how easily the monohulls were flopping over. I can’t be sure their masts were fully embedded in the water but it looked to me like a couple went over 90 degrees. This is what’s embedded in my memory from almost 30 years ago

[ozsailer]

Still asking - does anyone actually know what the cause of the capsize was.


Greg H
Lagoon 440