Agree Chris, traveller centered most of the time. We sometimes let it out a bit if it's really light conditions and we want to go deep.

It's also useful in pre-start manouvers (if we want to be pedantic). But otherwise, it's not used much anymore on a two person boat.

As I know nothing about gymnastics, what is graded E, F and G !

As for the traveller, in the normal turn of events the traveller stays central. In a gust the only thing to do is go with it and then (If possible) dump some traveller. If VERY windy then the traveller might be eased off to de-power and make things a little more manageable (I usually sail on a large lake and so it can get gusty and shifty and you just need a litte extra safety margin), however traveller needs to then be centralised before the gybe!

My Nacra 5.2 does have some weatherhelm issues because I haven't figured out a rigging setup that allows me to fulling lower the rudders but still tight enough that they will pop up when I release the line.
I also sail on a friends H16 that used to have a rediculous amount of weatherhelm. He tried all kinds of adjustments and it turned out in the end that the person who set the boat up before he bought it had the rudder arms reversed. When he corrected it, the problem all but disappeared.

Catamaran sails are always high aspect ratio, low draft, draft forward sails. These are designed to be sailed with less twist. If you trim off wind by centering the traveler at all times and then easing mainsheet to stop luffing on the lee side of the sail, your sail will have excessive twist for it's design. Monohull sails are typically cut for this type of trim, but then what choice do they have? The traveler on a monohull is very narrow compared to a cat's. This is regarded as one of the catamaran's other chief performance advantages over the monohull besides righting moment, that is the ability to pull straight down on the mainsail when off wind. This is due to the traveler track being as wide as the beam, and of couse the skipper has to use this width by easing the traveler out from center and sheeting the mainsail straight down. It only makes sense. I can refer you to any of several well regarded texts on sailing written by great and well-known sailors.

Have I got it wrong?

Jimbo

With no spin - I agree - traveller further out - you don't want too much twist. With a chute the apparent wind is so far forward there is no need to travel out (unless it's really light) and only minimal twist is required which can be supplied by slightly easing the sheet vs. upwind. In either case (spin/no spin) I'd just set up the sail to keep the tell tales happy at upper and lower luff and the tails off the leech streaming with the occasional curl to leeward.

Traveling down too far with a spin will pinch off the slot between main and spin. It's a good way of temporarily depowering the boat if you need to correct a problem (e.g. cleaning weeds off the boards or rudders). Just oversheet the spin and travel down and the boat will slow right down.

Yes of course, just as a jib acts as a slat on an airplane wing, keeping flow attached at higher angles of attack by bending the airflow more sharply, so a assym spin acts as a 'super' slat bending the apparent wind around even farther.

But consider the context of this thread. The guy is a new sailor on a Prindle 18. Now I don't know for sure, but I'm betting he does not have a spinnaker. He has too much weather helm sometimes. What would you bet it's that he keeps the traveler centered all the time, which is the wrong way to sail his boat as equipped?

Jimbo

P.S.

Flumpmaster,
Your avatar makes me dizzy, but then I haven't had my evening coffee yet

I wrote toe the rudders, but I meant raking the rudders forward. Asymmetrical boats need weather helm to sail efficiently to weather. According to Catamaran racing for the 90’s raking the rudders forward does not reduce weather helm it just reduces the feeling of rudder helm. They suggest playing mast rake before rudder rake to eliminate the drag. Obviously, don’t over do the rudder rake you still want some feel.

Jim, I never center the traveler unless I am right on the wind, even then I fear hooking my leach so I travel out slightly to if I see my one telltale on the leech acting up (Wally Myers suggested that and in light winds it sometimes does). I trim my lower telltales with the traveler and my uppers with my main sheet being absolutely sure never to stall. Then I set my jib to maintain the correct slot. Downwind I set my sails to maintain an apparent wind of 90 degrees.

For any catamaran w/o a spinnaker, you do.

Witness a Hobie 16 in optimal downwind trim:


The main needs to have two tell tales up high (if you look closely at the photo, there's one right above the sail insignia and another in the panel above that) to set the twist.

Twist in the main (in varying degrees, depending on the wind strength and sailplan) is almost always needed to account for the vertical change in apparent wind.

Mast rake is about the only way to alter the Cl on a beach cat other than easing the traveler. Altering the Cl defintely changes the helm. The P18 does have a heavier helm than the other Prindles even when your are sailing it right. Prindle put really long rudders on that boat to keep the angle of deflection low and prevent stalling the rudders. The 16, 18-2 and 19 have short little rudders by comparison.

Jimbo

Yes, some twist is good. But if you always center the traveler, for all points of sail including reaches in moderate or more air, you will be allowing too much twist for most cat sail cuts. With spinny boats the apparent wind is clocked around so high on the mainsail, the traveler is centered even when reaching. Other than watching the telltales, one way to know you have it set up wrong is excessive weather helm on an otherwise correct (no rudder rake/tow wierdness) boat. You can get any boat to have a heavy pull on the tiller, just head off the wind (no spinny) and keep the traveler centered and ease only the mainsheet. You get loads of weather helm.

Jimbo

In the picture of the H16 in downwind mode, it looks to me that even though they have some pretty decent twist, they are still travelled pretty far out. I've never sailed a spi-rigged boat and I have always been told to travel out downwind, travel in upwind. Most of my sailing is single-handed (150#) and I find that this flattens the sail for me so it helps to ease the traveller as much as possible.

Rob V.
Panama City
Nacra 5.2

In the picture of the 16, they ARE travelled all the way out.

That's me driving at the Hobie MidWinter's East (leading that race, BTW )

Here's the photo before I jibed:

That Kirk Newkirk in 2nd; Bill Jeffers in 3rd. Look at how high #'s 4 and 5 are sailing.

I tend to carry a looser rig in those conditions, which lets it flop forward, thus there's a lot of space between the blocks. Really powers up the rig.

I'd never do that in any kind of waves when it's blowing that hard (about 12-15 kts). You'd be asking for a swim.

You can also see the tell-tale placement better in that photo.

Why were the #4 and #5 boats sailing so high. Was it because they were behind they had to sail more aggressively?
Also, what was you apparent wind angle at that point in the run?

-Rob V.

this thread went from cleating the main to travler position to rudder rake. apparently all inter related subjects.
when i sail the TheMightyHobie18 on a solo in a breeze the traveler goes down past the hiking strap whilst sailing to windward, and the boards go most of the way up. i may not be making that much ground to windward, but at least i can stay out sailing.
when sheeting w/2 hands, the old fiberglass tillers were great for dropping the tiller between the big toe and the one next to it. an extendible tiller is kinda fat for doing that though. the old TheMightyHobie18 used to be fastest to windward in a breeze with the crew playing the travler, but some cats are faster when you leave the traveler alone and twist off the top of the main to windward. the only cat i sailed w/o spi. that wanted the traveler pulled in down wind is the Gcat. they are so fast downwind that you need to travel in on the downwind legs.
mainsail twist is fast. the question is how much twist?
the top af a windsurfer sail never ceases to amaze me. how can something so ugly be fast?

Its funny to write this down, as I do this without "thinking".


Tacking:
-Slowly steer into tack, keep steering throughout the entire procedure.
-Come aboard when boat is facing the wind, or beyond, depending on the conditions.
-Look forward as much as possible to avoid getting disorriented.
-Give about 20cm of mainsheet, switch hands so that the mainsheet is now in your new front hand.
-Pass tiller accross, keep steering.
-Quickly sheet in to build up speed.
-Attach traphandle to harness.
-Put feet on the hull's edge, kick out and pull on the mainsheet while doing so.

If I want to use both hands to pull on the sheets I lock the joystick between my upper-arm and body, tried doing it over the shoulder but that doesnt work for me. What's also very important when sailing solo it to have good gloves that give 100% grip (So you can hold the sheet with two fingers!). I've use quite a few and price doesnt mean a thing, now I use what I saw the Olympians use which is a sort of rubber coated wool glove. They're cheap too, about $7/€6!

They're made by the French company Plastimo. (16645 - Slip-proof gloves, Size M).
http://www.plastimo.com/catalogue/p...roof%20gloves&ref=16645&LangID=1

IMHO that beautifull A-Class video wouldnt work on my boat, he came in much to early with the traveller not centered.
When he goes accross, his boat has lost all speed but because that thing is so damn light it just explodes when he pulls two feet of mainsheet! (Anyone have a diagram of that mainsheet system?)

I can vouch for the effectiveness of those cheap gloves - been using them for about a year. We cut the fingers off 'cause it's a bit warm in Texas

Chris.

We had our first really good day of the season Sunday. It was blowing about 13-18 knots with sustained gusts around 20 and not a wave in sight. All of your tips worked beautifully. I was going out on the trapeze much more smoothly after tacks.

Thanks for the help,

Matt