I watched a guy nearly capsize right in front of us

[Dave_S]

Originally Posted by tomfl

OP has a cat; a Schionning Waterline 1480. A really nice cat IMHO. I doubt he disparaging catamarans; rather questioning the wisdom of flying a hull under the conditions at the time.

Definitely not :-) and not critical of the skipper either, he can sail it as he sees fit, so long as the crew understand. I'd sail with him.

Really I just wanted to share the experience without being criticle of anyone or anything. It could have been any boat that was being sailed that hard. Or any boat hit by a big gust. I bet he learnt more than I did.

We didn't experience any gusts the wind seemed fairly steady, I believe the slight change of course was all it took to make the difference (tip the scales).

What has really stuck with me is the speed it lifted, nothing like the YouTube visions I've seen this took maybe 0.3seconds to go from just lifted to 35°.

The release systems like myocean lnked to, or something simpler maybe a good back up for cruising.

[valhalla360]

Originally Posted by tomfl

If it was an R33 I would not bat an eye, if it was a Gemini I would be shocked it held together.

Really a meaningless post without knowing the type of boat.

Actually, heard some years back about some guys who bought an old gemini, stripped out the interior to get the weight down and used it exclusively for racing and they would fly a hull occasionally.

Just unloading our livaboard stuff, it's amazing how much faster ours was. We did that a couple times at the end of the season when we had pulled most of our stuff of before haul out.

Also the manufacturer did tests at the dock using a truck with a tow rope attached to the mast to show that it was strong enough...

I would have no worries about the boat breaking up from lifting a hull.

But back to the point, intentional is wildly different from accidental.

[Tupaia]

We need more info on the boat.

A cat with fixed keels will be very very close to the edge when flying a hull. It will also be less responsive to the remaining rudder because of the longer keel about which the boat has to rotate.

A cat with boards. Racers who regularly fly a hull will have the leeward board down but because of the high aspect ratio of the board, rudder response will be more sensitive and give better control. Cruisers with the windward board down will in theory have an additional release element when the board clears the water and the leeward hull slips sideways. If you want to try this, do it on someone else's boat.

So what boat? keels? boards? which board? lots of questions.

[rmlarson1098]

Originally Posted by myocean

So, the UpSide Up anticapsize system is probably really a good idea.
UpSide Up anticapsize

Didn't Donald Crowhurst come up with something like this? Back in the 'Golden Age' (late 1960's) of sailing?

[earthbm]

The estimated 35 degree angle may have been “Apparent Heel Angle” (AHA), assuming the swell was large enough. This would explain the speed with which it happened (just swell passing from under the windward hull).

Not really a dangerous situation. Falling 10 degrees off does suggest entering the “death zone” though... so I might be wrong

[sailingchiro]

I am not too worried about a hull getting "light" but rather the other hull getting "heavy". I like to look at my aft sugar scoop steps and see how many are under water. One, no problem. Two, time to reef.
Have pitchpoled a beach cat and never want to do it again.

[tomfl]

Originally Posted by earthbm

Attachment 201702

The estimated 35 degree angle may have been “Apparent Heel Angle” (AHA), assuming the swell was large enough. This would explain the speed with which it happened (just swell passing from under the windward hull).

Not really a dangerous situation. Falling 10 degrees off does suggest entering the “death zone” though... so I might be wrong

I have read that it is not just the wind in the sails but also the wind that gets under the bridge deck and lifts it up that causes cats to flip. In the pix you posted it shows how the wind would not only get under the bridge deck but the face of the wave would redirect the wind upward instead of hitting from the side.

Truth be told most accidents like flipping are not caused by one thing but a combination of things. In addition to a gust hitting the sails, wind redirected upward to the bridge deck, the angle of the face of the wave the boat is on needs to be considered. While I agree with your comment that the angle of the wave face may have reduced the risk of flipping it could also increase it.

[Snore]

Was the boat reefed? At 25kts AWS most boats call for a third reef or deeper.

Would be curious if the sheets were clutched or on the winches. At some point the person at the helm should have had an “oh ‘turds’” me money and tried to blow the sheets. With that load, taking them off the self-tailer would have caused them to dump.

Unreefed? Clutched sheets? Would make it sound like an operator issue.

[Dave_S]

Originally Posted by earthbm

Attachment 201702

The estimated 35 degree angle may have been “Apparent Heel Angle” (AHA), assuming the swell was large enough. This would explain the speed with which it happened (just swell passing from under the windward hull).

Not really a dangerous situation. Falling 10 degrees off does suggest entering the “death zone” though... so I might be wrong

I think what might have happened, happened just after your sketch when the loaded hull on top of the wave then past the crest dropped into the trench while the mast stayed in place.

Originally Posted by Snore

Was the boat reefed? At 25kts AWS most boats call for a third reef or deeper.

Would be curious if the sheets were clutched or on the winches. At some point the person at the helm should have had an “oh ‘turds’” me money and tried to blow the sheets. With that load, taking them off the self-tailer would have caused them to dump.

Unreefed? Clutched sheets? Would make it sound like an operator issue.

Interesting question because at the southern mark it was a 180° turn transition from downwind to upwind. So we passed them as we were going upwind and they were still headed for the southern mark and it looked like 2 reefs. Some other boats that were at the southern mark said they thought they had 3 reefs after they turned. I was keeping an eye on them as they were the likely boat to catch us and they didn't seem to be making much ground if any, until suddenly they were. When they passed us just before the northern mark they looked to have only one reef. It seems they shook out a couple of reefs at some stage.

I'd guess the sheets were on the winches as the main wasn't released until the boat was already descending or maybe even after it landed. In the short time it took to go up you could let a sheet go but no way you could do it if the sheet wasn't already in your hand.

[catsketcher]

I think the diagram is almost opposite to what likely happened.
Cats have very large righting moments and a very high rotational inertia. But a beam sea can rotate the boat sideways easily. The resonant frequency of my 38ft cat is about 0.5 hertz. In large swells my cat does not resonate with the waves.
But in small seas my cat really gets in synch with beam seas. This that the boat in question could have been rocked by a series of waves that amplified each other.
Also another effect is the reduction in stabilty off the back of the wave. As a boat falls down its weight reduces, this reduces stability. The combination of resonance and stability reduction could push a hard driven boat over the edge.

[chrisr]

sorry but i do not believe that any CRUISING cat will lift a hull due to wind alone. i feel strongly that my sails and or rig would go long before such happened (LOA 12m / Bm 6m / disp 7.7mt)

of course add sea state and it's a whole different scenario...i'm just talking wind pressure here.

[thinwater]

a. I consider a cat that cannot lift a hull in a fresh wind to be undercanvassed. That is NOT to say you shouldn't reef, it saying that with less sail on a shorter stick she is going to be underpowered most of the time. Many chartr designs are like that.

b. My PDQ would lift a hull in full control. But it would be simple to reef well before that. When it lifted a hull (just a foot or two) I was pushing hard, but under control. It's fun, but you need to have learned the craft on a smaller boat.
c. I keep the sheets in cam cleats, not self-tailers, when pushing hard. I also reduce the number of turns by one. Yes, I would have the sheet in hand, if I had been skimming a hull for a period. Obviously.


I'm guessing they intended for the hull to come up just a tick, but perhaps a gust hit at the wrong time, and it went up fast.

[Simi 60]

Did someone let Geoff Cruse get control of a winch handle ?

[Factor]

Originally Posted by Simi 60

Did someone let Geoff Cruse get control of a winch handle ?

Now that is funny!!

[tomfl]

Originally Posted by chrisr

sorry but i do not believe that any CRUISING cat will lift a hull due to wind alone. i feel strongly that my sails and or rig would go long before such happened (LOA 12m / Bm 6m / disp 7.7mt)

of course add sea state and it's a whole different scenario...i'm just talking wind pressure here.

Have to agree. I had a block with four sheaves and the pin the sheaves mount on gave way when I was hit with what I thing was a micro burst, easy 50 knots plus. On inspection there was a crack in the stainless steel pin and some rust so it had been weak for some time. But the only way to inspect it was after it gave way and the sheaves were released.

I always got the impression Seawind cats were over built and the mast looks like it would take Paul Bunyan to bring it down, same for the boom and heavy rigging. But there are lots of small parts like where the sheets and halyards connect to hold things together that would probably go first. I have never come close to lifting a hull in my Seawind. Most folks agree that Seawinds are not condomarans like FPs and such. I have to wonder just how many cats are capable of lifting a hull.