Had my first races for BISC's (my home club) season on sunday. Was a beautiful day and a stark contrast to saturday, which was rainy and 30+ knots on the bay, being sunny, 33C, and unfortunately almost no wind. The first race at 11 am resulted in all boats going backwards when the starting hooter was sounded, and as such was abandoned. A slight sea breeze developed and a second race went underway at about 2pm, with winds around 5 knots with the odd 7-8 knot gust, and moderate tides.

Having rarely raced in this kind of weather (most of the time i race its 10-20 knots due to sea breezes), i found i had a lot of trouble with my sail trim in these conditions, not to mention im a heavy crew (95 kg), which really doesnt help in these conditions. Further more, this was the first time id used my spinnaker in anything under 8 knots of wind.

Looking back on my performance (a very experienced maricat sailor/club champion etc, kept up with me upwind, a big shock, i normally blast away from him, and even more shockingly, kept up with me downwind, he ran square, when i was under kite!!), i believe i was for most of the day chocking my main, both up and downwind, and running far too high downwind with my kite.

Fortunately, my girlfriend and her dad were out on a little hire tinny to get photos of the racing for the club, and as such has given me some good photos to review my boat and sail trim settings, which i will post here to receive advice/feedback on.

Ill start with upwind.
Upwind, in light conditions, i find my self having to point almost directly into the wind in order to get the leeward telltales to fly, or ease the traveller out considerably.
I find that when i try and ease main sheet a little, i slow down, so how do i remedy this, i know im over sheeted and choking the main, but when i ease the main sheet i seem to go slower. is it that i dont have enough twist in the light stuff? How much should i let the main sheet off? Should i let the main off alot and keep the traveller centered to increase twist? I know some people say in the very light stuff u actually have to pull downhaul etc on harder, but at what point do u do this? whats the difference between light (no downhaul) and very light (downhaul on)?

Upwind photos:

Note: When viewing the photos, when you first go to the links below, you can click on the photo it self, and the photo will be reloaded and will allow u to zoom in to better see things like traveller position, telltales etc.

http://img8.imageshack.us/my.php?image=dscn1282rc3.jpg

http://img8.imageshack.us/my.php?image=dscn1281hu8.jpg

http://img10.imageshack.us/my.php?image=dscn1283ex7.jpg

Downwind, i found i could get good speed with the spinnaker, just not in the right direction. In fact, i at one stage, when the wind was very light, must have been 2-3kts, on an upwind reach, i hoisted the spinnaker, and had better upwind speed than one of the nacra 5.8s, i must have been about 50-60 degrees off the true wind, with the apparent wind at about 35-40. However i found it very difficult to go on a decent downwind angle, i tried heading up to build speed and then bearing away, but in order to get speed i almost had to head up to an upwind angle and was then only able to bear away to about 110-120 off the true wind, so in essence, my downwind runs consisted of lots of fast reaches, but i must have covered a huge distance, as when i got to the bottom mark, id find that i hadnt increased my lead on the maricat who just laid on his tramp and ran square at a very leisurely pace downwind .... reminded me of the turtle and the hare, quite embarrassing actually.

After talking to one of the nacra 5.8 sailors, who didnt run their kites on the day, i spoke to him of my sail settings, and what i was focusing on in terms of sail trim. From everything i had heard from people about spinnakers, was that u had to have the traveller centered or close to it, and the mainsheet on fairly tight to not allow backwinding on the main, and also to stop the mast from bending. What i found was that in order to get the leeward telltales on the main flowing, i had to pull the spinnaker sheet on moderately to strongly, but then the spinnaker leeward telltale would stall, so i would head up, to get both the spinnaker and the main leeward and windward telltales flowing, this gave great speed, but i was essentially then just going back and forth across the course, and not making much ground towards to leeward mark. So explaining this to the nacra sailor, and asking him about his settings, he told me he doesnt even look at the leeward spinnaker telltale, and that as long as it has shape, and the windward is flowing (air is coming into the spinnaker) all he focuses on is his jib and mainsail telltales, and that in the light stuff he lets his traveller out to the footstrap and has his main let off considerably, and downhaul off completely. So my question is, what is usually the optimal settings for main sheet, traveller, downhaul, outhaul, mast rotation, spinnaker sheet and spinnaker halyard (luff tension) settings, in very light, light, moderate and strong winds. Also i am wondering if anyone can give a good explanation of how spinnaker luff tension affects the spinnaker. From what ive read from a Singapore catamaran clubs site, when interviewing greg goodall about the viper spinnakers, greg said that increased luff tension (pole kept low and halyard pulled on tight) actually causes the spinnaker to curve more and take more shape, and that easing the luff tension causes the spinnaker to get flattened? This almost seems backwards to me logically, so im wondering if anyone can give me a different explanation.

Downwind/Spinnaker Photos:

http://img14.imageshack.us/my.php?image=dscn1191sp1.jpg

http://img7.imageshack.us/my.php?image=dscn1220sm8.jpg

http://img14.imageshack.us/my.php?image=dscn1224iv3.jpg

http://img22.imageshack.us/my.php?image=dscn1226ft8.jpg

http://img23.imageshack.us/my.php?image=dscn1231ty4.jpg

http://img10.imageshack.us/my.php?image=dscn1233xb6.jpg

http://img25.imageshack.us/my.php?image=dscn1240fc6.jpg

http://img7.imageshack.us/my.php?image=dscn1245xh1.jpg

http://img7.imageshack.us/my.php?image=dscn1193gb6.jpg

http://img11.imageshack.us/my.php?image=dscn1285yq9.jpg

http://img18.imageshack.us/my.php?image=dscn1287pz9.jpg

Accidentally dropped the tiller extension in this photo, which touched the water and then got dragged right back to the rudder housing, did this a while back in much much stronger winds going much much faster, which is why my tiller extension is so bent, the drag from the water bent the tiller extension around the tiller bar and rudder housing. Havent been too keen to try and bend it back too much (it bent almost into a half circle when it happened) for fear of creasing the metal and either breaking it then and there, of having it break out on the water.

Anyway, any advice and comments on the photos and what i can do to improve my sailing is greatly appreciated.

Thank you.
Michael.

First things first, sit further forward. Arms on the foredeck. Dragging the transoms around is very slow.

As you said it looks like you are choking the main, but only a little. Ease mainsheet a fraction and pull on some outhaul, a gap of about four fingers should be maximum, one finger minimum. It looks like you have about a hand-span gap in those photos.

Upwind in light stuff the key is to maintain speed.

Ease everything out downwind with kite in light winds. Sail almost square, maybe a bit higher. "High in the lulls, low in the gusts. Maintain speed."

Those last two images look like good kite sheeting but the main looks too tight. Ease traveller a lot and sheet a bit to allow some twist. In that second last photo, I reckon you should easily be able to see the mast around the leech.

Some of the photos show the spinnaker way over-sheeted. "If in doubt, ease it out."

"" - Common catch phrases to remember.

I love light winds. Almost everyone else hates them and lose concentration so it is easier for me to do well. Plus you break less gear.

i havent had much experience with kites on mozzies, but have sailed about 10 seasons on 14'skiffs so kites are much the same, in real light breezes, i.e. less than 5 knots, downhill runs you could try "goosewing" the kite. that means main all way out on correct side, as if ruuning main only and then run your kite on opposite side. pulling apparents around doesnt work on real light days. your better off travelling shortest distance and exposing maximum sail area. but dont do it over 5 knots as these mozzie masts wont stand up to much more, if you get a squirt, traveller 1/2 out and main sheet on!!!!!!!!!!, the leech tension is only thing to stop rig going over top

These are all good answers and it sounds like you've figured out some of the answers yourself.
Certainly there comes a point where the wind is too light to get the apparent wind working for you and you have to just go downwind and ease the sheets in that case.

Don't get too nervous about having to pull the main in and on when the wind increases. Sure you should, because that is where the sail should be set for speed, but the Mosquito mast is very forgiving and is not dependent on the mainsail to stop the top breaking off. I'm sure it could be done but no-one has managed it yet! Have a look at this South African Mosquito - full-bore with the main out. It's not a good look but the masts seem to cope alright.

Upwind in a drifter, you need lots of downhaul to let the sail twist and flatten. Then centre the traveller, and pull the mainsheet in but only so much that the sail can still twist off. Then just steer to the tell-tales.

As little puffs of wind come by you can pull tension on the mainsheet so long as some twist stays in the sail, but make sure you let it off again as soon as the puff passes.

you ar emost definately correct tim, but i am talking a decent squirt, as in 15 knot sea breeze kicks in half way down leg. that S.African mast does look dodgey but.

That's interesting about the effect of luff tension on the spinnaker shape, and I guess it makes sense.
With the spinnakers Lindsay makes we usually aim to have enough slack in the luff to be able to grab a handfull and turn it 180 degrees (probably about 200mm of slack). This is the way the spinnaker is designed to set so we don't really play around with it. I think you have a tighter luff than this from the photos - and the head does not seem to even go all the way to the halyard pulley. It looks like your pulley could be set lower. Hard to say from a photo taken in no wind though.

Thanks for the advice guys, its all greatly appreciated, so if theres any more, even if it seems trivial/obvious, please keep it coming, even if its something i already know, its good to get it confirmed by other sailors. What about mast rotation upwind in the light stuff, and also when flying the kite downwind, is it (rotation) always let off regardless of the wind conditions?

Heres the link to that article about what Greg Goodall said about the Viper's luff tension (which from what i believe is a very similar designed spinnaker to mine, from what greg told me when i speaking to him about my spinnaker, it would be very similar to the viper design, just smaller), so if anyone can add any extra comments on what greg said, that would be great, as i said early, i dont fully understand the impacts of luff tension on spinnaker shape just yet.
There was another article as well, but i cant find it at the moment.

http://boatsbikesboards.wordpress.com/2008/09/06/f16-spinnaker-conversation-with-greg-goodall/

Michael,

I agree with the comments above except that I know very little about spinnakers.

Mast rotation upwind in light winds is an interesting problem. You need enough to let the wind flow around the lee side of the mast but not too much so that the airflow stalls. Before the start of a race try altering the mast rotation with outhaul, downhaul and mainsheet set in one position and see what difference it has on your speed and power. You may be very surprised with the results.

I remember doing this on an A class cat and the results were astounding. The A class has a wing mast so the results were magnified. Simon also had some comments on the forum about the time his rotation control line broke in light to medium conditions and it felt like the Mozzie just took off.

Try to remember what settings you had that gave you the best speed and power for the wind conditions. Good luck with the experiment.

Regards,

Peter

That's interesting about the spinnaker luff tension. It was the opposite effect when I was sailing dinghies. In the 125's with a symmetrical traditionally set kite, we would drop the pole on tight windy reaches to reduce the overall "power" of the kite. The major effect was that the sheeting angle was lowered considerably which opened up the leech a lot, hence depowering the kite.

It was amazing to see my brother with very light crew (40-45kg) in 20 knots on a shy reach blast away from everyone at a national titles heat because he had dropped the spin pole till the luff was tight. Only the heavy crews could even keep the kite up with theirs set normally, let alone be in full control and keeping up with my brother. Everyone else had to drop their kites and two sail reach to the bottom mark. It was phenomenally quick.

And don't forget to sit forward!

It reduces transom drag, may reduce wetted surface area, and reduces weather helm (which adds drag and slows you down in very light winds).

I would rate it more important than the sail settings in light winds. You can play with sail settings, but if you're not sitting forward the perfectly set sails will be wasted. (may be a slight exageration, but you've still got to sit forward)

Hey there,

Had the boat out today with kite and went OK but thought could be a whole lot better.

Couple of questions -

Should current mossie kite size, mine is Irwin and just made in Jan 09, go to halyard pulley at maximum distance up mast according to mossie build specs?

Mine is short by maybe 300mm or so - bit hard to judge really but certainly not up to pulley - if I do the luff is way to tight.

What sort of position are people working with for pulley height up mast?

I am working with a sloop bridle and have the pole under the chute throat as per VMCA web page setup - is there a new and improved way?

Any comments would be welcome.

I put my pulley 1m above the hounds as described on the VMCA's Spinnaker Rigging Section. When i pull the halyard on all the way the knot in the halyard just above the head of the spinnaker does make it to the pulley. Maybe your pole is too low? i based my pole height off of the photos on VMCA with the end of the pole around the same height as the gooseneck on the mast. From what i understand, in light weather you want the luff tight, halyard all the way on, and in heavier weather you can let it off a few cm's.

Something is seriously wrong here. The spinnaker should go all the way up to the pulley and then you should be able to grab the luff and twist it around 180 degrees in your hand - that's how loose it should be. The luff of this spinnaker should never be tight!

Things to check.



Your halyard pulley looks high in this photo. It should be 6380mm from the main beam. Your bridle and pole also look too high (not what you want to hear!). The minimum height of the ring where the jib attaches is 380mm above the deck. It doesn't need to be this low, but I'm guessing yours is a lot higher.

Is your mast raked back? If anything it should probably be upright or only raked back a little.

I think you should also measure the length of the luff of your spinnaker. It should be close to 6950mm.

This is the look you are after:

Tim & Michael,

Thanks for response.
Gives some items to check through.
Will measure kite luff, do not think Irwin would have got that wrong but will check.
The mast position is still a work in progress as had no reference point when rigged for first time the other day, so I may stand it up a little more.
The pole is set up to sit just below chute mouth and connects to main beam, so I will check bridle height as it may be much higher than the 380mm.
The pulley position, I thought, is as per specs but maybe I got that wrong - it was very late at night when fitting that.
As chippies say measure twice then cut - maybe I stuffed it up.

Yes I have been on the VMCA site and checking the photo's of other rigs to work out what was amiss.

Thanks so much for your info - it makes it that much easier to sort problems out.

Hey there,

Have done some checks.

Kite
Luff - 6870mm, leech, 6180mm, foot 3170mm
Pulley height - 6350mm approx.
Bridle height - 500mm approx.

Having kite right way around when rigging it up - no!

Yes, OK hand me the dumb award, in all my haste with rigging on Sunday I have realised I had kite around wrong way.

Maybe I should have sailed backwards......?

I will however adjust bridle height down some and establish a correct mast position.

Thanks guys.

Oh, and just remember - don't let me rig your boat.......

Cheers,

Hah! That's a good one!

At least now we know what it looks like!

Yeah i thought it looked a bit funny in the photo with the luff looking very short and the leech looking long and saggy, was going to ask if it was the right way around (i had a little trouble the first time i took my kite out of its bag, does ur kite have a luff rope? the goodall spinnakers as well as a luff rope have a white strip of material sewn down the luff as well with further helps distinguish luff from leech). Oh well, at least you know theres nothing wrong with the kite it self (much better on the wallet).