Just finished my 2nd day on a cat ever and find it troublesome to tack my Hobie 17 with uni rig.
What is the best way to tack in medium winds? Slow turn, boards out, ..? Any tips or reference to a sailing guide?

Thanks for your help!

Bolivar

plates stay down, moderate turn, rudders must not go all the way over or you will stall. Keep mainsheet tensoion in till you are past head to wind and then let out a foot or so (or more if windy to stop capsize)

Key is keeping it smooth

Same as in other post but you may want to try to let out the traveller right after passing through the wind instead of the mainsheet itself. Is easier with a bigger overall effect and doesn't stuff up you proper mainsail trim you had before your went into the tack

Wouter

as you turn keep you weight toward the rear and what would be the new leward side, at the last minute as you oass through the eye move to the other side and onto the new tack.

Wouter,

You know, I have never considered that,......and as you kow, I try everything.
....so there is better results with the trav instead of m-sheet for tacking?

As to the original post,..keep practicing,..you will be fine.

Try to read the chapter in Rick White/Mary Well 'Cat sail. of the 90's"...there is a chapter on Uni's,..a good place to start.

regards,
Bruce
St. Croix X-17

I recorded some videos during my training with the A-cat. I took a short piece of the video that shows a tack and saved is a Windows media player format.

The reason that I mess with the centerboards during the tack is not to make the tack faster but to increase upwind speed. The tack is a bit slower when you mess with the centerboards.

Use the link below:
Low bandwith (512/512)
http://webbo.dyndns.org/sailing/

Better bandwidth:
http://www.acat.vallagruppen.com/svenska/bilder.htm

Select the video tack.wmv and save it on your harddrive. Use the file on the harddrive when looking at the video, don't play it from the server.

/hakan

@ haken,

Why move the (new) windward board or are you using it as a bit of extra gust response if the hull goes that high ?

@Bruce/Wouter

Disagree about the traveller. I feel that letting a bit of main off allows twist in and ensures that the sail is driving early and allows re-attachement of the airflow quickly. If you can get the traveller to exactly the right spot it might be quicker, but in any waves, the whole rig / boom is going to shake around more with traveller out thus loosing air flow/attachment.

My 2 pence / Cents

I only use two centerboards in light to medium upwind conditions. At boatspeeds of 9 knots and above one centerboard is enough. One reasone for this could be that I'm a quite light A-cat sailor, only 72 kg, wich reduces the side force that I can generate. Heavier sailors needs both centerboards most of the time.

During starts and in bigger waves I use both centerboards.

/hakan

>>Disagree about the traveller. I feel that letting a bit of main off allows twist in and ensures that the sail is driving early and allows re-attachement of the airflow quickly. If you can get the traveller to exactly the right spot it might be quicker, but in any waves, the whole rig / boom is going to shake around more with traveller out thus loosing air flow/attachment.


Well, I don't know yet. The reason behind working the traveller is not to have early power but to keep up the rate of turning all through the tack. Also my sailcombo is rather sensitive to mainsheet trim. I will do alot to not have to stuff up the setting I optimized on the preceding upwind leg. Also I can easily get my traveller back in the old position while I find it takes alot more time to sheet back to the exact right amount of mainsheet tension. Especially when sailing with a jib the repositioning of the traveller is very easy. Here my car is always centered on a upwind beat. You can't pull it past centre can you ?

I do admit that I'm in the experimental stages regarding the traveller use when looking at catrigged sailing. However I do think that the mainsail slows down the turn away from the wind after teh bows have crossed through it. Letting out the traveller without flapping the mainsail should allow the boat to turn away from the wind quicker and farther. Then bringing it back in and heading back up a little bit will power up the boat very quickly and have you speed away without losing time on mainsheet trim. Besides if my mainsheet tension is still on than the battens in my main prevent flapping. In my setup the mastrotation is independent of the traveller position so when I let the traveller out I also reduce the draft in the sail significantly thus reducing drag. The same manouvre allows the battens to pop over.

So I'm not looking at quick reattachement but rather a quick unhindered turn through the wind and all the way to the next course, preferably even overturning the tack. Thus keeping the exact same trim as before the tack but now hanging off the other side. I accept that I may loose something by powering up later and pointing lower but I also understand that I gain alot of time by not having to find my optimal trim again and I'm in the trapeze and away quickly as well.

Right now on my F16 I find that I'm using the traveller more and more. Just because the sheetload on it is very moderate and because it often gives such good responses. My traveller car runs really smooth. But again I think my mastrotation setup plays a role in all of this. I'm also experimenting with working the traveller during the large gusts upwind. I try to have my rig deal with the little gusts automatically or by steering through them. It is in handling the big gusts that I'm trying to see if working the traveller is better. Here I'm sure my mast rotation setup helps alot. I can really see the top of my mast bend off to lee when leech of my mainsail is brought more in line with the fore-aft axis of my mast. The bending away of the top takes the top of the mainsail with it. So instead of controlling the heel by twisting off the squaretop using sheet tension I'm now experimenting with controlling the bending off of the whole top of my mast and sail combo using the direction in which the leech is pulling. I think one can only do this in an effective way on flexible wingmasts which hardly any current catamaran design uses. I already found that underrotating the wingmast is not a problem; there doesn't seem to be a drag or turbulence penality as is the case with a tear drop shape masts. It is a really remarkable rig.

I do realize that all this may well not work on the Hobie 17 that bolivar is using. BUT I found that the H17 has a serious issue with completing the turn and coming out of the tack. I figured that by having the main weathervane off over its full length, not just the top, may help this design coming out of the tack. Afterall the bottom of the mainsail isn't resisting the turn anymore. Just an idea.

Wouter

wouter

Brobu,

See my other post. I think some of it may work on the I-17 as well as it has a relative flexible mast as well. The FX-one is probably better of using the old methode.

I trust you see the intent of the experimental manouvre ! It is to speed up the tack itself and keeping the mainsail trim unaltered.

But I'm giving myself some time to evaluate the effectiveness. The first tries are always awkward and effectiveness is only proven or disproven after one has really tried to make it work.


Also I found that I can tack my F16 doublehanded in (selftacker) sloop mode without touching any sheet. Just by carefull steering and modest roll tacking. However I'm currently slow to come out of the tack as the main powers up to soon. The jib doesn't get enough lead time to power up. Hence the "let the traveller out a bit" experiment. Thinking it through it occured to me that the same procedure can be expected to work while sailing without a jib. Still, the fact that my mastrotation is independent of the traveller/boom position may really help as well.

Wouter

Thanks for your video, considerations and suggestions, I will give it at try next weekend.

B

Wouter and Scooby,

You know, the time for me to do a complete tack cycle, that would be from full throttle starboard upwind - tack - full throttle port upwind.....takes alot of time.

A big part of it is repositioning the mainsheet to max speed mode,...a real big part,...just to 'get the cat happy' again..

If one could 'do it' with just the trav.......what a nice way to be!

So, I am going to work on it too.

Of course, by Aussie T 4.9 Uni champs standards, my mainsheet is upside down,...ha,.......I want to try this also,....they put their cleat of the mainsheet assembly,.at the boom end!....makes sense too...

Happy Sailing and Hurricane season ends in 17 days

Bruce
St. Croix
( my boat went from an' I 'to an' N' to a 'F' in about 60 days,..so now I call it the 'X 17' )

Bruce......

You should be aiming for around 10 Seconds wire to wire and fully powered up. My best so far is 10 seconds in about F4 on flat(ish) water - the joys of a GPS on board. It shows all the bad tacks and gybes

But it also shows the good ones and how fast you are going

I am aiming for Sub 10 after this winter

Here is how you should roll tack the boat.

Enter the turn with speed. Main will be flat and in HIGH GEAR.

Begin the turn with steadily increasing pressure on the helm to insure the water stays attached all the way through the turn.
Move aft at the same time.
Ease the mainsheet just as you go through the eye of the wind.
(By easing the mainsheet, you are straightening the mast, making the sail fuller and easing the leech. You have now shifted down into SECOND GEAR. Just like a race car driver, you need to gear down into the turn and power out of it.)
Note that the leech is tight in HIGH GEAR. And when you begin the turn, the tight leech helps the rudder by weathervaning the boat to windward. But, once through the eye of the wind, you no longer want that tight leech -- the reason why the traveler idea will not work.

How much sheet you ease is dependent upon the boat design, wind, waves, etc. The less you leave out the faster you will re-accelerate. However, boats like the H17 need to have more sheet eased. The more you leave out, however, the more the boat will slow down and the more time it will take to accelerate out of the turn.

Back to weight Distribution. Once the boat is on a close-reach heading, straighten the rudders, switch helm and sheet amidship and go forward, ooching forward as you sit. All of this will get you through the turn faster and speed out of the turn quicker.

I spent a lot of money and effort to develop this technique and it can be thoroughly seen and understood on our new video. Check it out at http://store.catsailor.com/tek9.asp?pg=products&grp=178 and it is available in PAL Version as well for our friends overseas.

Good luck,
Rick

Brobu,

General idea is this.

-1- Trapping of starboard full speed
-2- Looking for a spot to tack.
-3- arriving at the spot and get in while letting the traveller a bit out. I'm hoping this will power down the rig enough to get in.
-4- Steer up while pulling in the traveller to get the last bit of power pushing me around the corner
-5- When head to wind, uncleat the traveller and let it run out a little just so it weather vanes with the wind.
-6- Continue to tack while staying on the old luff hull- roll tacking
-7- When the baot powers up a little again slowly move over to the other side.
-8- Continue the turn while hooking on gently
-9- get out and pull the traveller in simultaniously. Heading to the right course and preventing the main from stalling.
-10- Trapping of port full speed.

Apparently all this in 10 seconds flat, leaves about 1 second per step.

Again this is experimental and so I may change a few steps.

Wouter

My version :

1, Flat trap on the wire (full speed)
2, Rudders over (still on the wire) and move back to the rear beam
3, Wait till your Bum gets wet (still on the wire)
4, Move inboard, letting a little mainsheet out as you go head to wind but wait (in lighter wind) will the battens have popped on the new tack
5, Cross under Boom, change hands for mainsheet and tiller
6, Hook on and out you go, sheeting in as you go (if required) and move forward. Check Compass or GPS for new heading etc.

"-4- Steer up while pulling in the traveller to get the last bit of power pushing me around the corner"

Wouter and all...When I tack I put the sheet in my steering hand so that as I push the helm down the sheet is eased at the same time. This is the opposite of what Wouter is doing in his point 4.

The reason for this is that as the boat turns through the first half of the tack its rotation causes the apparent wind to go aft. So easing the sheet actually maintains better sail trim and drive through the tack. In light air the effect is greater than in strong wind. Just try it and let us know what you find.

That's one of the problems with the H17. You'll do it easily with roll tacking. Get Rick White's video on tacking and you'll see how easy it is to keep the boat speed up through the turn. Couple of tricks: Keep weight to rear as you turn the rudders (do not jam them); When the boat is directly in the middle of the turn, loosen the mainsheet about a foot; when the boat is on the new tack, get your weight to the windward side and up towards the front crossbar. Slowly, trim the main again.

Wyatt

I have never sailed a Hobie 17 myself, but I want to tell you the advice of the late, great Carlton Tucker about tacking the Hobie 17.

He said, right after you cross through the eye of the wind, you need to let out a lot more mainsheet than you would with a sloop. He recommended approximately 4 feet in light-to-moderate air to up to 8 feet in heavy air and chop.

He said that in heavy air, when he was trapezing off the wing, he would stay out until the boat went through the eye of the wind, and then as he went to center to exchange the tiller, he would basically just bring the sheet with him -- about 8 feet of it -- and then when his hand reached the mainsheet cleat, he cleated the sheet, exchanged his tiller, and grabbed the sheet again right at the block and went back out on the other side, pulling the sheet with him.

Rick does not agree, because he thinks that is too much sheet to let out -- slows the recovery from the tack. But I am sure that 1 foot (as somebody recommended) is definitely not enough on a Hobie 17.

And Carleton would have been appalled at the idea of letting out the traveler instead of the mainsheet. He believed the twist in the sail is very important for helping it to bear off on a reach to get speed after the tack.

Now, I am only submitting this as something additional for Bolivar to try. But if it worked for Carleton, it can't be too far wrong. The most important thing is to keep the sheet tight and not let any sheet out until AFTER the boat has gone through head to wind.

I would think the best way to approach this would be to let out more sheet than necessary in each of various wind conditions and then keep perfecting your tack until you are able to achieve the best possible speed through the tack letting out the least possible amount of sheet in each wind condition.

Just my 4 cents.