Catamaran surfs into rocks

[paxfish]

Originally Posted by Blue Stocking

" Always steer into the skid "

Assuming you have steerage.

I wonder how my cat would behave on such a wave. I presume that initially you are moving faster than the water, as the wave builds on your stern the water starts moving faster than the boat, and that IN BETWEEN, there is a period where no water is flowing past your rudders, and you have no steerage.

And during that time, the captain is furiously trying to steer to starboard, but the water has started to move faster than the boat, hitting the backside of the rudder and pushing him further to port.

Broach City....

Do I have that about right?

[Polux]

Incredibly accident with a relatively small wave!!!

It seems the accident was caused mainly by entering the channel at very low speed and that allowed the wave to take full control giving the big difference of speed between the boat and the wave.

To pass an entrance like that max speed is of the essence and a bit of luck too

https://www.youtube.com/watch?v=ZgeLJHe7M9w

[UpOnStands]

SV "Kamanu" in the photo has both engines driving hard.
Backwash in the channel must be fierce.
https://www.google.com/maps/@19.6692...8!8i2736?hl=en

[seasick]

Armchairing this is pointless but going full astern with the starboard engine at the first sign of broaching may have had a positive effect.

[Polux]

Originally Posted by seasick

Armchairing this is pointless but going full astern with the starboard engine at the first sign of broaching may have had a positive effect.

No I don't think so. The problem here, besides speed is that he takes the wave slightly sideways from the beginning and when the boat goes sideways descending the wave there is not much he can do.

If he had took the entrance perpendicular to the waves, or if he had took the have perpendicular and when down changed slightly of direction I think that he would not have a problem.

Before they invented those light kayaks for surfing I used to surf waves on a big and heavy kayak. Nothing to do with a surf board, more with a boat and when you go down on a wave sideways you cannot change suddenly of direction. Only when you are down and slightly ahead of the wave that is possible. They just had not the time for that.

[donradcliffe]

There was some rumor that one of the engines was not working on the cat, which would have made maneuvering more difficult. The pictures showed that the boat was in little pieces by the next morning.

There was a recent posting on CF extolling the virtues of cats which claimed they don't broach...

[lateral]

Originally Posted by Polux

No I don't think so. The problem here, besides speed is that he takes the wave slightly sideways from the beginning and when the boat goes sideways descending the wave there is not much he can do.

If he had took the entrance perpendicular to the waves, or if he had took the have perpendicular and when down changed slightly of direction I think that he would not have a problem.

Before they invented those light kayaks for surfing I used to surf waves on a big and heavy kayak. Nothing to do with a surf board, more with a boat and when you go down on a wave sideways you cannot change suddenly of direction. Only when you are down and slightly ahead of the wave that is possible. They just had not the time for that.

+1
You need the rudder full immersed & not bow down or your toast.
Every one on the transom please!
The "kickout" needs to be done with hull speed also, once you have x component sideways you aint going to push thru the white water hard to port.
Bad luck and commiserations to owner, even to someone that surfs regularly
it isnt hard to get committed setup a little awry.
And eat sh_t.

[Bulawayo]

I wonder if she was motoring on a single engine?

Originally Posted by Seaslug Caravan

Apologies if its already been discussed.
Salvage efforts underway for catamaran near Honokohau Harbor - Honolulu, Hawaii News and Weather - KITV Channel 4


Second video down page shows complete surf.

[alansmith]

If you watch the news channel this boat is a charter cat...the type used for evening sunset sails. So, this crew had probably done this entrance a zillion times. They were able to remove the motors before she completely broke up...according to the news. Bad juju that day.

[CLady]

This part of the Kona coast easily fosters complacency because it is usually quite mild and these cats doing the snorkeling and sunset cruise excursions every day can easily get lured into a sense of ease and not be sharp on considering how a swell could change everything. Entering that harbor can be tricky with this swell and being in the center of the deeper water entrance is prudent. Those "pretty blue swells" can seem innocuous but they can pack a lot of power.

[roverhi]

Talked with someone familiar with the boat and captain. Unfortunately he chose a line into the harbor that favored the north side. With virtually no underbody save the rudders, the reverse flow of the wave under the rudder turned the boat toward the rocks and it skidded to it's destruction. They speculate that the only way he could have gotten out of it was with asymmetric engine thrust. With the disaster happening so quickly, that would have been a reaction that probably would only have been possible if he'd had his hands on the engine controls and had preplanned a response.

Seems that partially deployed dagger boards would have helped. The owners of the trimaran I occasionally crew on always leave the center board down under power so the boat has something to pivot on in a turn and maintain heading rather than skid on top of the water.

[Palarran]

Originally Posted by donradcliffe

There was a recent posting on CF extolling the virtues of cats which claimed they don't broach...

I didn't see that posting. Do you have a reference to the tread it was in? It would seem that any person who has sailed, or even studied catamarans, or monos, would know that it is possible to broach one.

But in this specific case Don, do you see the boat actually broaching or are you just taking the opportunity to bash the cat crowd.

Made it to post number 22 this time

[boatman61]

He'd have been better off locking the wheels centre and steering by motors alone.. rudders are useless in these circumstances

[Seaslug Caravan]

Originally Posted by boatman61

He'd have been better off locking the wheels centre and steering by motors alone.. rudders are useless in these circumstances

Could one assume then that an engineless or even single engined catamaran
is a dangerous beast then?

[tp12]

Originally Posted by Polux

Before they invented those light kayaks for surfing I used to surf waves on a big and heavy kayak. Nothing to do with a surf board, more with a boat and when you go down on a wave sideways you cannot change suddenly of direction. Only when you are down and slightly ahead of the wave that is possible. They just had not the time for that.

Digging your paddle into the water and throwing your weight over will bring you around if you dig it in hard enough and hold it there. Which takes a bit of strength and confidence but it's possible. I grew up on Australia's Gold Coast messing around on rescue boards, kayaks, anything I could get my hands on, to let you know I'm speaking from experience.

Of course, and as you allude to, the new light kayaks make it a very easy proposition and are a lot of fun.

I am in the camp of wondering if the use of the engines would have helped spin him around. It seems logical. Not knowing, of course, if there were any engine issues at the time and I've never tried it myself. If someone wants to lend me their Cat I'll have a crack at it though