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Old 13-06-2018, 06:48   #16
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Re: Motion In The Ocean...

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Originally Posted by JPA Cate View Post
Big Beakie has the right of this, that the distance between the seas has a huge effect on how the boat behaves, mono or cat.

Ann
That's what I figured....
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Old 13-06-2018, 06:53   #17
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Re: Motion In The Ocean...

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In my experience, that is not an uncommon general experience in those conditions - a corkscrew motion that some find quite disconcerting if going upwind into a steep, short chop. One theory is that it is related to the leeward bow hitting the wave after the windward bow that causes the jerking motion.

In your particular case, 6 knots in that much wind seems slow so you were probably over-sheeted and/or pointing too high. In any case, you can often get a much more comfortable ride with a better VMG by falling off a bit. We would always experiment. In our case even with that motion we could happily leave cups on the saloon table, it seemed that people were more impacted than things.

And I guess slightly for your encouragement here are a few videos, the first two of us sailing upwind at 8 knots in 20 to 25 knots of breeze in the middle of 5 days upwind sailing between Bermuda and the Azores - the most upwind we did in the 3 1/2 years we were out cruising.

https://youtu.be/TWEUyKMk0z4
https://youtu.be/rY4-lNKxF4E

And the last one is of the sailing you want, going 7 knots in 8 knots of breeze heading from Panama to the Galapagos Islands:

https://youtu.be/uLkOWqehUCs

Mark.
Those videos were more of what I had suspected! And several people have mentioned our "slow speed"... Our skipper seemed to think we were going fast, but I know cats usually do better than that. I'm still thinking that our sail trim was way off.

Another point was that we had both a kayak and Paddleboard tied to the railings on the starboard side. that is a lot of windage. How much would that have affected our ride?
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Old 13-06-2018, 06:59   #18
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Re: Motion In The Ocean...

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Is there a way to minimize that movement on a cat? There's part of me that believes that we exacerbated it somehow by the way we were sailing, or trimmed, etc...

(just as a note... we all managed the motion well... but I just would like to know how to smooth it out in case we are crossing, and someone needs to sleep, or we have guests who might be susceptible to motion sickness, etc.. )
Often not, because you are on a given route to somewhere and the sea state is what it is. If sailing more casually then maybe.

Beam Seas. Worst case for a cat. Potentially unpleasant in a mono too, but worse in a cat due to two hulls out of sync in the wave form and being beam-to...you can get a rather nasty snap roll going with each wave set. A significant course change is the only solution.

Close Hauled. Potentially next worst case, but not necessarily. Whether it is unpleasant depends a lot on the sea state and boat. Conditions that will make the given boat have bridge deck slamming are the worst, but that can usually be reduced or eliminated by falling off some or actively steering for the waves, if your route allows it. I once had to slam straight into steep short period 8' seas for 12 hours in a cat to avoid a storm, big bridge deck slam with every wave, ...very unpleasant. But, big smooth swell or long period waves and it can still be a pleasant ride.

Confused Seas. With significant confused seas you can never get the two hulls in sync, so the ride is always a bit arythmic. Course changes often dont help much beacause the seas are confused no matter your route. Sounds like to me this may be the conditions you had?

In some cases, powering the boat up and getting more boat speed/inertia can help. For example, in smallish confused seas this will help the boat punch thru them and be more stable. The opposite for big confused seas, slowing down may help. In some cases, like going to weather against steep seas, slowing down may help also.

All other things being equal a longer cat with higher bridedeck clearance and more mass will handle most sea states better.
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Old 13-06-2018, 08:42   #19
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Re: Motion In The Ocean...

Personally, I get dizzy and nauseous on a catamaran due to the jerkiness; possibly, I’d get used to it over time. That doesn’t mean other folks will have the same experience. The motion on a cat versus that of a mono, or different types of monos effects each individual differently. There’s no right or wrong answer, since the motions are different.

Seasickness is a personal experience, select the boat that’s right for you.
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Old 13-06-2018, 09:17   #20
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Re: Motion In The Ocean...

38’, did it have a “flybridge” as well?

The best advice we received was “buy as much waterline as you can afford.”

I’ll catch some flack for that but it was good advice.

We ended up at 50’ with no regrets.

I also can’t speak to newer cats that look like loaded up three story condos. To be fair they are built for a purpose and do it well.
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Old 13-06-2018, 10:01   #21
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Re: Motion In The Ocean...

Ideal conditions for going to windward in cat (or mono): fresh trade winds behind the reef (so almost no seas).

https://www.dropbox.com/s/h4p7tkwb6n..._high.MP4?dl=0
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Old 13-06-2018, 10:22   #22
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Re: Motion In The Ocean...

I motored straight up the California and Oregon coast last October/November on my 35' Island Yachts Packet cat. Wrong time of year but there you go. Needed to be done. A trip I'd normally do in 5-6 days took 5 weeks due to storms, mechanical issues.

Had a lot of big storms moving through I had to wait out, 20-25' seas etc. Going around Cape Mendocino the predicted winds were 10-15 knots and seas to 8'. Actual conditions were winds steady at 38 knots with gusts into mid 40's. Seas 12'-15' from primary direction (head on) with 2 other swells 6'-8' coming from 2 different directions. Less than ideal conditions lol. I slowed the boat way down out of fear of losing the temporary radar pole and new radar. In these seas my cat rode surprisingly comfortably due to it's hull shape. Island Packet Yachts made the Packet Cat for a few years in the 90's and added a partial 3rd hull in the front 1/3 of the boat which splits the wave and gets rid of most/all of the bridgedeck slap. It rode more like my 40' full keel mono. I was pleasantly surprised as it was a new to me cat.


Later in the trip. expected winds 5 knots, we got too far offshore. Winds were offshore and blowing a steady 45 with very short, very steep choppy seas. That ride was hell no matter how we chose to take the waves. Usually on a cat you want to take the waves at 45 degrees. Everything that could fall was launched and it was several miserable hours until we got close enough to the beach where there was reduced fetch and we could turn north again. This could have been made easier I think if I'd had more speed and could have stayed on top of fetch. I had a totally green crewmember I'd picked up on the way after breaking my hand and the mainsail (getting replaced) is a broken roller furler main that takes 3 people to put up. Just wasn't an option.

Realistically beating into the wind on any boat is not the fun point of sail.
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Old 13-06-2018, 12:13   #23
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Re: Motion In The Ocean...

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38’, did it have a “flybridge” as well?
No flybridge. We are looking at buying a 45-ish foot cat, so we will have a little bit longer water line. Even the 38' Lagoon felt like a tank!! We would have chartered a bigger boat, but the larger boats were just cost prohibitive.. I have a love/hate relationship with the flybridges. I LOVE the visibility, and additional seating area... I'm sure when sailing, everyone would be up there. But the additional windage, and safety risk in bad weather? kind of cancels that out...
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Old 13-06-2018, 12:48   #24
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Re: Motion In The Ocean...

The only time I have sailed in a cat was out of Hawaii. Just a few hours in heavy chop but the next day I felt like I had been rode hard and put away wet. I wonder if Justify ever felt like that? At least he probably got good massages. What a horse!
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Old 13-06-2018, 12:53   #25
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Re: Motion In The Ocean...

I've sailed extensively on both. The cat is jerky for sure and a little tiring on the legs due to that. The mono however does the slow roll thing which I dont like and hobby horses much more too. Some worse than others of course. My hips get sore trying to stay vertical on a mono too, often from the companionway. The mono may stop short in a hard short chop also going to weather. The Cat glides over better.
No free lunch, but I prefer the motion of the cat, albeit it's a bit tiresome.
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Old 13-06-2018, 13:04   #26
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Re: Motion In The Ocean...

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Originally Posted by scarlet View Post
No flybridge. We are looking at buying a 45-ish foot cat, so we will have a little bit longer water line. Even the 38' Lagoon felt like a tank!! We would have chartered a bigger boat, but the larger boats were just cost prohibitive.. I have a love/hate relationship with the flybridges. I LOVE the visibility, and additional seating area... I'm sure when sailing, everyone would be up there. But the additional windage, and safety risk in bad weather? kind of cancels that out...
I was surprised by how Flybridge (on the boat I was on) changed my view of such.

I think anyone would need to sail on one of the boats equipped with a flybridge (enclosed or with Bimini top) to see how remarkably nice it can be. On the boat I was on (Lagoon 52F) the owner and all three of the crew felt the Flybridge was the nicest feature of the boat, the nicest place to be, and very comfortable (shade, protection from rain, etc.). During a 24 hour day, I think the crew spent about 20 hours each day in the Flybridge (at helm or reading or lounging, etc.).

The boat I was on had a large, wide, platform (like a bench seat) that had a thick comfortable cushion on it and some folding padded "sailing" chairs too, on which four or five people could sit comfortably behind the wheel. So, the owner/helmsman was always WITH the rest of the crew (or family) and together close. That is different from a single, more isolated raised seat for one or two at the helm (with others in a lower level cockpit). While sailing, it meant everyone was "together" and this was conducive to fun conversations, extra eyes on the horizon, etc. I saw this as very beneficial.

Since so many large cats are used for local or coastal sailing or short hops in the Caribbean, I think the "risk" is worth it for most sailors, given the balance of risk or cost/benefit. Of course some will never want a flybridge due to opposition to the way it looks (it is high) and because of concerns about windage and some because of cost.
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Old 13-06-2018, 14:21   #27
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Re: Motion In The Ocean...

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Originally Posted by scarlet View Post
Those videos were more of what I had suspected! And several people have mentioned our "slow speed"... Our skipper seemed to think we were going fast, but I know cats usually do better than that. I'm still thinking that our sail trim was way off.



Another point was that we had both a kayak and Paddleboard tied to the railings on the starboard side. that is a lot of windage. How much would that have affected our ride?

6 knots through the water going to windward in only 15 knots of wind (apparent I assume) with choppy seas on a 38 foot cruising cat is plenty of speed. Better trim might have given you an extra 1/4 knot on average. Was your skipper an idiot during the charter that you don’t trust what he told you?

Let’s be real here everyone; I don’t understand why people think this was slow for UPWIND sailing on a loaded 38 foot cat with relatively wide hulls and the extra drag of mini keels.

Yes, cats are generally faster than their equivalently sized (LOA) mono cousins, but not in the smaller sizes and certainly not always even in larger sizes. Lighter wind upwind, due to the drag of two hulls and lack of sail area, is usually the area of worst performance for cruising catamarans.

Overall, you experienced a point of sail that most acknowledge as the least comfortable on a cat and often not much better on a mono. The two best strategies to be more comfortable were probably not available to you - changing course or adding 10 feet to the hulls. Skinnier hulls rather than wider hulls also help, but then you really need extra length to have the carrying capacity.

Another strategy that might have helped that I don’t think has been mentioned is running a single engine to keep the boat driving through the chop. The extra power tends to damp the movement. Opinions vary whether it’s better to run leeward or windward engine - it depends on how the boat is balanced under sail and which engine causes the least extra rudder angle. Since your skipper didn’t opt for that he must have thought he had plenty of power from the sails.

Regarding the windage of the board and kayak, I’m sure they weren’t any taller than the cabin, so they wouldn’t have added any significant extra windage.
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Old 13-06-2018, 15:13   #28
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Re: Motion In The Ocean...

For my two cents - I don't agree with much that has been said here, but like Big Beakie, I am from a multi background that values performance in all its forms over room.

Hobbyhorsing was sorted out in the early 80s when designers worked out that high volume ends produced cats with better pitch damping. Designers also learnt quickly that weight in the rig or the ends of the boat increased hobbyhorsing. If you look at the cats from designers like Crowther and Chamberlin you will see the lengths they went to to get the weight central - the diesel motors on many designs are in the middle of the boat. Weight low and central.

Getting weight centralised and increasing end volume, along with a low windage deck profile, and efficient rig will help any cat reduce its motion. The is basic physics and you can't get around it. When you put weight in the ends, or increase the height of the CG, or increase air drag, you get poorer dynamic performance.

Then have a look at the track the French charter cats design type has pushed cat design along to. The GC is higher, the motors are now often right at the stern, weight is up at the ends, the air drag is much higher and rigs have been pushed up to avoid flybridges. The boats are more Winnebago than touring car. Winnebagoes are great, but they are Winnebagoes.

No one would expect great driving performance from Winnebagos and condocats can't be expected to pitch damp like a Crowther 105 or Deguello. There is a real reason why the great designers like Lock Crowther and Chamberlin, Schionning drew the boats they drew - because they were sailors first and found it impossible to compromise the dynamic performance of their cats. That is why I like sailing these type of cats - great windward performance, great light air sailing, smooth helm, great groove - just like a nice touring car.

So if you want better sailing, try a better sailing design, with daggerboards, a nicer rig, no flybridge, low windage, weight centralised. That is what I would do, and it was the norm for most of multi history. Now we are in a different world where interior performance is paramount but it was not always this way. You won't just go faster, the boat will feel better too and sailing it should be a joy.

I hope the condocat owners don't get upset but the physics is undeniable and we can't choose the science we agree with. My cat is smaller inside and it can't carry as much weight as a fatter hulled cat - basic physics I can't deny either. But as to other parts of your question.

Cats usually move more quickly than monos - but sometimes you can trick things. I rarely sail beam onto chop. In some places where the chop is vicious I will sail slightly upwind and then slightly broad rather than beam reach. Beam reaching on a cat can get awfully tough as the stability is huge and the boat complies to the wave surface with massive accelerations - point up slightly and then bear away later to get one bow or stern to meet the wave first. I even do this in sheltered waters and turn our cats into power boat waves rather than take them side on.

I always try to remove any windage I can if I need to sail a reasonable distance. Kayaks on the sidedeck will increase parasitic drag and slow you down. This will also increaes tacking angle and leeway. So pop the kayaks on the dinghy at the stern (I hope they are light).

Don't stow anything heavy up front, or way down aft. The only things that should be up front are fenders and pool toys - light things go up and down really well so keep bows light. I once moved a 30 kilo dinghy from the bow of my 31ft tri to the cockpit when sailing upwind, it changed how the boat behaved, she went from a nasty cantankerous thing to a real lady - only 30 kilos ( on a very light boat agreed) 5 metres too far forward. However this meant the tri needed to bury its bow deeper every wave to produce an extra 1500 Newton metres of torque. With the weight around the pitch centre the bow dug in far less.

It seems like you like your sailing. I would get down to a multi racing club and sail on some nice multis - you might really like it. You can get some that sail incredibly well and still have heaps of room. You don't have to get a production condocat. It suits lots of people but I would much rather sail a Sayer 40 mono or Searunner 37 tri, because they are great boats, rather than a cat that didn't make my heart sing.

The photo attached is a favourite of mine. We are daysailing down the East coast of Australia and have been on the wind every day for weeks. The boat is loving it and we are still having fun. She is in the groove and I am just part of the scenery - smooth, and fast, raking in the miles - to windward.

cheers

Phil
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Old 13-06-2018, 15:24   #29
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Re: Motion In The Ocean...

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Old 13-06-2018, 16:35   #30
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Re: Motion In The Ocean...

Not the first time this has been mentioned but the first thing that caught my eye was 6kns in 15kns of wind. My rule of thumb is that any decent cruising cat should be doing 1/2 wind speed up to around 10kns. At that point other things come into consideration. I single hand my Seawind 1000 with 1 meter sugar scoop added and have no trouble doing that. Once the wind hits 15kns+ i reef. As others have mentioned falling off or heading up not only can provide a more kindly motion but often increases the VMG as well.


Not saying there are not sea states and wind directions that make for an uncomfortable ride; but am saying a small change in course and taking in a reef or two often makes things much better. As you may have noticed there seem to be one group of folks who own cats and say it is fairly easy to get a comfortable motion on a well designed cat and another group of folks (who often seem to own monohulls) who find cats uncomfortable no matter what.


Another thing I would point out is that a couple of years ago I took a couple of extras from Hollywood out on my cat. Left BKH and sailed out the blue water of the Gulf Stream. The guy was loving it and as there were maybe 2-3 foot seas and 10-12 knot winds. The girl got seasick (maybe something to do with watching me eat left over pizza they had bought for me last night along with a couple of YooHoos. I mentioned staying above decks and looking at the horizon along with eating a gingersnap cookie or two might help. Instead she went below decks and lay down in one of the quarter berths in the bow. I mentioned if she stayed below deck the elevated master bunk amidships would be more comfortable but she insisted on staying in the bow.


So there are several things that can combine for folks having an uncomfortable ride. Not the least of which is that having a well designed cat and knowing how to sail it is probably the most important thing to have a comfortable sail. And trying to impose monohull skills on a cat often results in an uncomfortable sail.
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