Why Do Catamarans Motor Nearly 100%

[44'cruisingcat]

Well yes obviously they were motoring 100% of the time.


Did they have motors?

[colemj]

Originally Posted by 44'cruisingcat

Did they have motors?

Yes, 9 on each boat constantly running the hydraulic pumps. Keeping them in burgers and beer was quite expensive, even for a billionaire.

Mark

[0urh]

Originally Posted by downunder

Would be great to see some photos of Bob's new vessel.

I imagine it will not be slow.

Has the sails fitted, but still motoring

[beiland]

Originally Posted by smj

These are the 4' stern extensions we did on our Seawind 1000. As you say, it's like a little dock!
Attachment 114831
Attachment 114832

Nice job

[Factor]

Originally Posted by tuskie

....

Pollux, you may not have much practical experience with cruising catamarans, but Factor and others do. I'm sure that they, if honest, would admit to having seen many "fast" cruising catamarans made "slow" due to overloading.
Perhaps not.

Made slower - but not slow, a practical example might be attitude (you may have seen it in Manly) its a 16.2 metre Schionning G Force, close cousin to Mojo and Chill Pill. Attitude was built to be a performance boat with supreme comfort to be sailed by a couple. And the couple that own it certainly have sailed it, far and wide. I have crewed on it many times including some Gladstone races. It is substantially better finished and more luxurious than mojo and Chill pill, and they are almost always faster, and the owner has no issue with that, having said that I have done consistent plus 20s on her - between 22 and 25 knots for the 3 hours of my watch on a gladstone race, so even though she is quite a bit more luxurious, and indeed quite a lot heavier, she still isn't slow. when the owners cruise on the coast they budget on 100 mile daylight runs and that means leaving after brekkie and anchoring before dinner.

Conceptually yes of course you are correct that a heavily overloaded performance boat will suffer greater affects than a similar load on a wide hull design, but the reduction in performance is not necessarily huge, but it is noticeable. For ref Attitudes OMR weight is a little over 9 tonne and Mojo and Chill Pill are both a little over 7 tonne, Attitude is 1.2 metres longer than the others but with the same hull dimensions. So it sort of suggest you can through a tonne and a half or more on a boat like mojo and still go bloody fast.

[beiland]

Just happened across this quote from another subject thread this morning.

Originally Posted by David Tyler

There's plenty of evidence, both theory and practical, that a low quadrilateral sail (square sail, lug sail, gaff sail, junk sail) is both more efficient and easier to live with, downwind, than a tall, narrow triangle. C A Marchaj did wind tunnel testing on this many years ago. Some weekend cruisers never sail upwind, so they ought to be happy with such a rig, if they could break the triangular habit.

On the other hand, there's plenty of evidence, both theory and practical, that a tall narrow quadrilateral sail (AC wing and others) is more efficient upwind. Fast multis never go downwind, the apparent wind is always forward of the beam, so they're happy with the tall narrow quadrilateral.

In between, there all the folks like me who want to sail across oceans, up and down narrow rivers, through the difficult channels between islands where the wind comes at you from all directions, seemingly at once. To make us happy, the rig has to perform well and comfortably under many different conditions - which sometimes equates to fast, but not all the time. There's nothing worse in a cruising boat than having a rig which won't slow down. You wouldn't accept a car that only had two speeds - top speed and stop - would you? In the same way, a cruising boat must be able to sail at the right speed. That's why I'm interested to hear what the theorists have to say, but in the end, I'll be going for the moderate rig, capable in all conditions. There's a well-known phrase that applies here: "Good Enough".

The design of soft wing sails for cruising - Page 4 - Boat Design Forums

[Kenomac]

Originally Posted by Palarran

One thing is for certain in this whole thread---- we will never, and I mean never, see that video.

Never say never....

https://m.youtube.com/watch?v=roLIEIjsd18

[44'cruisingcat]

Seems to me you had your motor running 100% of the time....

[Polux]

Originally Posted by Kenomac

Never say never....

Nice video, but your wife seems as pleased as mine on those conditions

And even if upwind is not really close upwind where the fun (I mean for you) would be a lot more and the motion a lot more vivid.

I love going upwind with strong wind and that kind of sea, at least for some hours where, on a responsive boat, you pick your way, wave by wave, minimizing pounding and loss of speed while maintaining the boat really close to the wind. Pity my wife not to be of the same opinion in what regards fun, but that is comprehensible, since she gets seasick with the kind of motion tat implies.

She can take without problem big slow movements but hard against the wind with that kind of sea the movements are much sharper and faster and that is what makes her seasick.

That's a funny thing, regarding movements and seasickness, she does not get seasick on a car, no meter the turns a road have but if I start to drive my little roadster on a mountain road in a very sportive way, she starts to get seasick: the same kind of jerky movement, hard on the breaks, sudden lateral accelerations till 1G, from one side to another, sudden accelerations, that's what gets her seasick. Same on the boat, regarding sharp movements and seasickness.

[malbert73]

Originally Posted by Kenomac

Never say never....

Nice video. Blowing about 35? Your bimini showed how hard it was blowing in one shot when it was fluttering...


Sent from my iPad using Cruisers Sailing Forum

[Palarran]

Originally Posted by Kenomac

Well, yesterday was the first day in over four years where we got caught out in bad weather which lasted for more than 9 hours. We tried our best to make the right decisions to avoid most of it, but it was worse out there than forecast. Instead of a ten hour crossing in fairly nice weather which would have put us in a windy achorage, then had us starting out the day in a lousy tired situation, we carried on and ended up hitting 35-40 knots right on the nose for five hours... Then a continuous 25-35 for maybe another five hours. Twenty hours total, got in at 2am.

Our boat was a submarine at times.... i wouldn't have wanted to be on a catamaran during any of that. Or on many costal cruiser monos either. Eventually our luck ran out, but other than a shredded American flag... No worries, no problems.

Originally Posted by Kenomac

How does YOUR boat handle heading directly into force 8? Sustained 35-40 knots, 15-18 foot choppy seas. When I get to a wifi spot, maybe I can download a video of the encounter we had, wet on the outside clipped in and wearing a harness life vest, dry on the inside, no worries about safety and my wife casually reading a book in the cockpit up until she gets doused by a wave. That part will need to be edited due to the language content. :-)

We were able to make 3-4 knots of headway, which surprised us. Can your cat make headway in those condition? My inquiring mind would like to know.

Originally Posted by Kenomac

It definitely helped keep this thread at the top of the board. :-)

Now let me ask again... Can you contribute any, and I mean any personal experiences on how a catamaran will handle Force 8? My inquiring, psychologically deficient mind wants to know.

Please enlighten us all. Personally, I just can't figure out how a rectangular object with significant windage can punch holes through waves and wind better than a pointed object. Please tell us?

Originally Posted by Kenomac

While crossing the Strait of Bonifacio in late September 2015 on our Oyster 53 sailing yacht, we encountered Force 9.5 sustained (40-50 knot) winds and 20-25 foot (7-8 meter) seas. We expected 38 knots while threading the needle between two storm fronts, but instead... we got a little more.

Since the seas were going to be behind us or broadside, we had only our main sail up furled to less than 25%, and chose to have the staysail ready but to not use it unless we absolutely needed to do so. Our staysail furling line had issues and it was somewhat doubtful that I'd be able to furl in the sail. The 100hp Yanmar engine was running at 2200rpm (40-50hp) mainly to aid with steering. Mostly, we were surfing.

The Strait of Bonifacio is the passage between Corsica and Sardinia in the Mediterranean Sea.

Well Ken, I was wrong and we did get to see the video. It really is a good one so thanks for making it and finally posting here.

Of course you know that it makes me wonder though right? In your first post you said the wind was directly on the nose and your boat was a submarine in F8 winds (apparent or true?). Then your in 15 to 18 foot seas and surprised about making 3 to 4 knots of headway. Then it became a F9.5 SUSTAINED (didn't know the scale goes in half increments) with 20 to 25 foot waves and your boat is surfing (downwind?). Then at last you quite honestly post that during all this your motor was running at 2200 RPM's.

This all makes me fully understand why you think catamarans motor 100% of the time - you naturally exaggerate observations by 50%. So really, you have observed catamarans motoring half the time in the Western Med - yes, I agree and that is probably what we averaged.

[Kenomac]

Over the next couple of days I'll post the correct video of my wife reading while we're motoring into 30-35 knot winds on that particular day. It's very short and kinda funny. I knew you'd catch me on the details.

[Palarran]

I'll look forward to it. But hey, I really do understand your observations now. If you add in the exaggeration factor most all of us who have been cruising the Western Med would agree. It also makes sense why you don't see cats motor sailing when you are. With main sail furling it's very easy to put up some cloth, fire up the diesel, and putter around. With cat's it's more difficult to pretend to sail, so we just simply motor.

Originally Posted by Kenomac

Why is it that nearly every time I see a catamaran here in the Med, it's motoring from place to place? Even when the winds are favorable... they're under power. When we were looking for our present Oyster, I went on a test sail of a 45ft Leopard at the Annapolis boat show because I want to like them with the enormous living quarters, but the thing sailed horribly.

I see many, many Lagoons around here, but nearly 100% of the time.... motoring with sails furled. Why is that? Do they sail that badly? Wouldn't motor sailing be preferable? Why not just buy a powercat if all they do is motor?

I really like the Sunreef powercat. Maybe someday.

Ken

[Polux]

Originally Posted by Kenomac

Never say never....

Now I am confused. You are motoring at 2000rpm here?

If so the engine would not appreciate at all that heeling angle in what regards lubrification, at least the ones I know.

[44'cruisingcat]

Well geez Ken, you said it was directly on the nose, but it sure doesn't look like it. Looks more like it was on the beam, or just forward of it.


We encountered similar conditions crossing to Vanuatu. For 3 days, the wind didn't drop below 35 knots. one day it didn't drop below 40. Peak we recorded was 48 knots.


At about 70 - 80 degrees true.


We didn't need to wear foul weather gear, because in our protected cockpit we didn't get wet. We cooked, ate hot meals, made coffee, could put our cups on the table without them spilling.


We DIDN'T need to run our engines.


I realise now I should have taken video, but at the time it really didn't seem a big enough deal to warrant it.