Why I Like Multihulls (Well, One Reason)

[Jim Cate]

G'Day All,

Interesting thread, many divergent opinions (as always), and even some useful thoughts!

One thing I'm surprised no one has mentioned: a few years ago some friends of ours in a Lightwave 38 cat DID flip when surfing across the Wide Bay Bar in the dark of night. It was apparently a "rogue" wave that popped up in generally more calm conditions, and Terry believes that he actually dug the knuckle of one bow into the bottom. Whatever the cause, it did pitchpole, and they were very fortunate to escape without significant injuries. The rig collapsed, of course, but there was surprisingly little structural damage to the hulls/deck/house.

Back to this incident -- while they did risk an out-of-synch bigger wave doing them in, their approach to the entrance seems to have been under reasonable control. In my viewing of the video clip there was no time when the boat seemed in trouble... the litle twitch was quickly corrected, and the rest of the crossing was straight and true. I have to admit that his claim that they never felt concern a bit hard to wear!!

Our boat is a lightish mono fin-keeler, and we routinely surf on ocean waves. She is stable enough in 3-5 metre seas that the autopilot is able to keep her straight. I recognize that bar waves may be steeper, but to say that only a cat can maintain control under surfing conditions is silly. Anyhow, since Insatiable is our uninsured home, we probably would not have attempted this crossing, but don't condemn this chap for what he did.

One last thing -- the use of drogues in such conditions.
We've heard of folks doing this, and it certainly could aid in avoiding a broach. However, by materially slowing the boat, it increases the exposure time. Any thoughts on this tradeoff??

Cheers,

Jim and Ann s/v Insatiable II lying Broken Bay, NSW, Oz

[Ozbullwinkle]

I have done a lot of bar crossings but they have been predominantly in powerboats where you sit on the backk of the wave & maintain your power so another wave cannoit catch up to you.

In my opinion Saltonay was just having a look & sizing up the bar and the skipper had not committed to crossing it. You can see that he is hardly moving at all then the wave pops up behind him and then before he knows it he is committed and cannot turn out of it. More good luck than good management in my opinion.

[Eleven]

I had a nice surf like that coming in past The Needles. Steering, normally marginal, was very good with the high boat speed, double the hull speed, and a very smooth pleasant ride.
This video has been fully discussed before on CF.

[dennisail]

I've been through that bar a few times. Its one of my local bars. Its normally easy. When I first saw this vid ages ago I thought he was very close to loosing it. It looks like the transoms come out and he looses steerage with the rudders. As the broach begins he gets traction with the rudders again just in time to prevent doom.

[Eleven]

A broach isn't too bad with a cat, the slew was probably largely corrected by the starboard rudder/skeg starting to bite, with some help from the helm. If she had gone broadside on she'd have rolled smoothly over the crest, the hul spacing making it not too violent. The only problem then is going in the wrong direction.

[SaltyMonkey]

Originally Posted by cat man do

On page 2 of the notes he talks of tanktesting hullforms in a wave tank at Southhampton.
He says that they could not capsize a catamaran in beam on seas using the largest wave generated, which equated to a 52 ft breaking wave on a cat with 40 ft beam (big boat)

Scaling this down he says that a typical 24 ft beam cat should be OK in a 31 ft breaking beam sea.

Compare that to a comparable sized monohulled powerboat that was easily capsized with a 25 ft breaking sea and a conventional 40 ft sailing mono could be capsized by a 12 ft breaking sea as was demonstrated in the fastnet disaster.

...And on the quarter or competing angles?

[Arch Stanton]

Originally Posted by Jim Cate

I have to admit that his claim that they never felt concern a bit hard to wear!!

Yeah considering he said he needed a very uncharacteristic 9:00am beer afterward, I have a hard time believing it either.

[Arch Stanton]

It seems pretty feasible that with training and experience, this wasn't a big deal for the crew of this boat. Maybe the beer was just for the adrenaline.

I think a good comparison is a cross-wind landing in a jetliner:

YouTube - Crazy 747 Crosswind Landing - HEP67

It looks insane and stupid but with proper training and thousands of hours of experience, the risk is so minimal that it's routinely done (with hundreds of souls aboard).

[dennisail]

Originally Posted by Eleven

A broach isn't too bad with a cat, the slew was probably largely corrected by the starboard rudder/skeg starting to bite, with some help from the helm. If she had gone broadside on she'd have rolled smoothly over the crest, the hul spacing making it not too violent. The only problem then is going in the wrong direction.

I dunno. I don't think it would have ended well if he ended beam on to that monster wave.

[senormechanico]

That 747 pilot did in the air what I do on water when I sail into my lagoon during a big flood tide. Ya just have to line up something as a range.
Good piloting.

[yachtyian]

Good Heavens! some of you guys are pretty hard markers. Ive just read some of your opinions and I feel like ive been pilloried.
When I brought Saltonay through the bar I fully expected to get right through without incident. The Seaway tower had advised us that the bar was settled and fine, five minutes later they came back and stated that they weren't so sure as occaisionally the waves got up they were not able to advise us that the bar was safe. for the sake of a good story, the t.v. reporter came up with a fair amount of B.S. I discussed the situation with my two very experienced crew and told them that under no circumstances would I attempt the entrance unless I had their full support to do so. Without hesitation they stated that they were happy to go.,,It was then up to me and after sitting for half an hour watching how the sea was performing, i elected to make the run. Saltonay performed brilliantly, a minor correction on the helm straightened her up. she did exactly what she was designed to do. Any half competent skipper could have done what I did. It was certainly an adrenalin rush, but I can absolutely state that fear was not an issue. It all happened so quickly that I had no time to panic or be frightened for my safety. inside the boat was a vastly different feel from how it looked from the shore......Give me a break guys I'm a quallified skipper with 35 years experience. If you had seen and been where i was at the time, I think your decision would have been the same. Incidently the bar was flat as a pancake one and a half hours later................ Ian Sloan....skipper of Saltonay

[Factor]

Ian - Mate - you are on a loser here. Instant experts will now pick apart your statement and crucify you all over again. People who dont even know which hemisphere the southport seaway is in will explain to you why you are silly. I admire your skill and your confidence, I have watched the video many times and have entered the seaway many times, never in quite as exciting fashion, but every time, its a good feeling to get across even when its flat. Like a few others here I looked at the video and thought that you did a good job in a good boat. I think the thing that some of the "experts" dont get is how much time can be spent surfing ina good size cat, surfing at good speed is not something to be feared if you have a good boat and do it often enough.

[Richard5]

This thread is entertaining if nothing else. It is all across the board; from surfing multis Vs monos, arguing wave height, how to measure wave height, learning to fly, cross wind landings, hull testing, and so on. And all from persons of varying skill levels and caliber of character. Some would go, others would not.

As for wave testing in a tank, keep this in mind before taking that data into the practical world. That is not to say tank tests are not informative but that the conditions are highly controlled. Compare that to the waters where on the open ocean you may encounter several swells each of differing direction, height, and period. Layer that with sea state from wind and current.

In essence I am saying data derived from hull tests in a tank may not transfer to actual conditions. Caveat mariner.

I have crossed many a bar under sail. I started surfing Hobies and Prindles in large breaking waves for fun. I have also crossed bars in breaking waves in monohulls as large as 65'. I am familiar with the various techniques and they do work however one should explore alternate methods suitable for changing conditions.

One method I found was to enter the wave at an angle then when the stern does lift to pump the rudder to hold an edge. When sensing the rudder becoming light (control force), "fall away" from the wave. This keeps the broach firmly to one side and allows for greater speed and rudder control. The angle is not very great, perhaps 10-15 degrees from bow on. Basically your track may look like a shallow S turn across the wave face. This will also keep the sails full when to the bottom of the wave. Your results may vary.

What I especially like about this method is it tends to keep the bow up until the wave dissipates and the stern comes down. Resume course, carry on.

[Richard5]

Originally Posted by SaltyMonkey

...And on the quarter or competing angles?

Stability testing does not test for every conceivable condition, regardless of how likely.

[Richard5]

JMolan, I got to hand it to you. Three times I was offered a position on crab boats and three times I turned them down. Highliners too! The 1st year I would have gone up there (if I accepted the offer) eleven men went into the water, none came out alive. I don't do well in frigid water.

I have kinda sorta regretted not going in those heady days. Guys were ending a trip with more money than most people will ever see.