Last Sunday we were sparring with our Blade against a Nacra Infusion. Our Blade is a US Blade with EU daggerboards. The wind was about mid 10 knots in the beginning going down to +/- 6 knots. The Infusion crew sails quite good within the F18 class and in regattas we normally finish behind them. We weigh 135 kg and they weigh probably 140 kg. Sunday was the day to check why we finish behind them ;-).

What are your thoughts on my ideas?

Upwind ->
10 knots: we could both double trap. Speed was the same. But they sailed higher. What could cause this? Below is the setting like it was on our boat and all seems ok? Am I missing something?
Our jib traveler was just before the 3rd hole on the track (I guess 15-20 cm out of the middle). All jib tell tales from top to bottom windward and leeward were flowing.
Mainsail centered, sometimes a bit of Cunningham. The top three batten telltales were flowing. The leeward telltale against the mast (spreader height) was flowing, the windward one was hanging down. Mast rotation was pointing to the daggerboards.

The wind dropped: the Infusion could still double trap, while we could only single trap -> we were slower. Again everything on board seemed to be ok but a huge difference in speed between the boats.

Downwind ->

10 knots: Kathleen trapping out, daggerboards about 2/3 to 1/2 up, mastrotation out, cunningham released, main centered, main sheeted so the tell tales of top three battens could flow. In 'gusts' I eased the traveller a bit. We were sailing the same speed again, but the Infusion could sail deeper this time.
Second run we left the daggerboards down and I played the main (left the traveller in the center). In the gusts I sheeted in and in the lulls I sheeted out, so the tell tales kept on flowing all the time. Now we sailed faster then the Infusion, but about the same wind angle as we did on the first run, so higher then them.

Any ideas or findings? I haven’t yet asked our sparring partner about his trimming so I have no input from him yet.

Gill

http://www.ahpc.com.au/Brett_SupportViper.htm

See if any of this fits.

Gilo,

how are your sails compared to his. Same age and use? An old spi vs. a new spi can be a real killer if you are at the same skill level. Same with an old jib compared to a new jib. If the skill levels are not proportional, the sails dont matter

Was the telltales on the main and the jib all lifting at the same time and on both sails when you got a header or when you luffed going to windward?
Did you sail with the windward jib telltales streaming horizontally or with them lifting 45deg? How about the jib telltales on the F18?

Besides getting the trim right, there is a skill portion as well. E.g. building and keeping the virtual wind when going downwind and findind the sweet spot both upwind and downwind.

Any video from the "event"?
(seriously, if you have a camera, and I think you do (?), how about fixing it so we can see the telltales and sailtrim).

I have found for me, that the biggest factor in how high I can get the boat to go (or low) is infulenced almost entirely by my stearing. Sail trim and rig tuning, while it needs to be close is not nearly as important as the rudders.

Matt,

could you elaborate on exactly how you use the rudders? I find it very hard to describe helming techniques, but perhaps you are better at it?

Hi Gilo,


Ok, first of all: F16 mast height is 8.5 and F18 is 8.9 or so, then they have 2 feet more length and more sail area. They are heavier, but I am sure this is over-compensated by the sail area and mast height (supported by your observation of double trap at light winds).
Maybe rotate the mast less (pointing to the rear beam) to have less drag in the lower part of the sail, but then maybe you are under-powered.


Seems that sheeting the main is better. I usually use gusts to bear away and improve vmg, instead of easing the treveller or main, but I am a absolute beginner of this type of downwind sailing. Again the F18 has more sail area and length.

The infusion is a new F18, so I assume that they have good sails, and as you say, they are a good team as well...

My "sparing partner" is a F18 and a T as well. I am not sure if this helps me really. Sometimes I have the feeling that I learn more, if we are (or I am) alone on the water. Maybe because I play less with the trim and concentrate more on tiller and main sheet. I "listen" (or sense, feel) more to the boat instead of looking to the others and asking myself what is wrong. Maybe nothing is wrong. I hope that that is not to philosophic and helps a bit.

Cheers,

Klaus

Good point. I think one must initially learn to sail their boat alone and feel for what works. If you always have someone else around which can make you over-analyze things a little. I almost always sail by myself with no one else around and if I do have a "sparring" partner it is a friend sailing an 18HT solo. I feel as though I have fairly decent boat speed, but hard to say. They always point higher than me (they almost have to pinch a little given the sail area) and run lower (same deal). I find the groove I normally try to find and go from there. If I tried to point with them I would go nowhere. I do think I had better VMG though. Hard to really draw a comparison though sailing against him. I have raced my blade once and then it was only for 1.5 races and I was overweight 2-up against the other blades which were uni.

Hi Klaus,

You're absolutely right that it's important to sail your own course and that sometimes it's better to sail on your so you start to get to know the boat.

@ Rolf:
When there is enough wind to double trap, I try to sail the windward jib tell tales 45°. But in less windy conditions I sail them flowing backwards.

I've been talking to the crew of the Infusion and they sailed there tell tales flowing backwards all the time -> so lower. Could the extra pressure on the daggers give them so much lift the end up saling higher...?

They also steer in the gusts, while I try to steer less and play the main. This could be a second reason. (and I guess Matt is also saying to steer instead of sheeting?)

Personally I have the feeling I can make the Blade go fast; I mostly have trouble finding the correct VMG.

Gill

I don't want to speak for Matt, but I find that there is a little give and take between driving as a response to a gust and sheeting to a gust. IMO, the goal when sailing uni (meaning it is hard to really sheet in and out in response to a gust) and you get hit with a mild gust is to try to anticipate the gust and steer with it- meaning heading up some. If you don't do anything then you end up heeling over too much which is slow and may lead you to dump too much sheet and setting up a see-saw type effect. When I sail solo my aim is to always keep the windward hull just a little out of the water. I can usually steer to make this happen with gentle movements of the tiller. Of course there are times when it is too gusty and too shifty to really maintain it but that is when downhaul and maybe dropping the trav 3-4 inches helps. I almost always sail with the trav down a few inches... I find it SOOO much easier to find a good groove that way (however, it would be nice to sail against someone on a blade sometime to really see whether this absolutely hurts my pointing and/or VMG). If you only sheet for the puffs then I think you will be missing out on some good lifts... IMO
I apologize if I am just stating what you already know.

An addition to my previous post.... there are people who only seem to sail when they are racing. Some have gotten to the point, I guess, where they are good enough to do only this. If I only raced I would go nowhere (bad habit of trying to do exactly what other boats are doing).

another edit: another problem with allowing the windward hull to get too high is that the rudder "detaches" from the water, becomes nothing more than a brake and negates your ability to turn down again unless you get to the way back of the boat and/or drop a lot of mainsheet. Seems like this happens more with my starboard rudder but I also wonder sometimes whether a different rudder would work better ? I am sort of hoping the Falcon has a different rudder (how about a cheaper version of the Bim rudder?)

Nothing is ever black and white, so the techniques that seem to work best for me I will try to relay as a generality as differing conditions require you to change on the fly.

Cat sailing is about leverage and hull speed. Turning your rudders at all presents added resistance to forward motion, plus the losses in trying to chnge dirrection. Therefore in general I find it much faster to attemp to keep from moving my tiller at all up wind. As I get tired this is harder to do and I find I am noticably slower and lower than I was earlier in the day. Anticipation of the gust is key to minimize how much sheet you are having to adjust to keep the boat attitude flat and constant. With varying pressure run your sail trim (and -very important- crew placement)to keep the boat in trim. With increased pressure you should let the boat accelerate, then let the lift of the foils ride the boat to a higher angle of attack. If you turn up with pressure before you accelerate, you will stall out the rig and foils, drop back down, have to reaccelerate again and end up being lower on the course than you were before, ususlly loosing at least 1/2 boat length in the process.

I typically sail with the jib. This need to be set up so the tells all stall properly, and then you can use it to watch whether the wind gusts are just preasure related, or if they are changing dirrection as well. If the dirrection is changing you can stear to it, if it is just a pressure change I do not steer.

Down wing ballance and weight seem to play an even more important role and there is quite a bit more tiller motion to maintain apparent wind, but it seams fastest when I can keep motion to a minimum. Always accelerate before turing, or if deceleration turn to go faster.

Unfortunately with the kids we are lucky to get out for the occasional race. More time on the boat alone or with a sparing partner is the best way to get better. My theory above is pretty general too and I do not ever manage to pull it off for very long, but we all need something to strive towards.

M

I have a question...

I have never heard of letting the windward Jib telltales flow about 45. I've always sailed with the windward telltales flowing back. Why would that make you slow? Just curious, like I said I've never heard that one before.

Here's another...

How did the boat "feel" to you?



Anyway, sail the boat and sail it as fast as possible.


Mike

Hi Mike,

if the windward telltale is flying, the wind enters the jib very smooth and produces a lot of lift and lift-induced drag. Letting the windwrad one stall a bit means a bit more drag due to stalling, but less lift and less lift-induced drag. At the end the ratio between lift and drag (from stalling and induced) is better that way. And the ratio of lift to drag is the key figure for making good vmg upwind.
Before letting the windward telltale rise, you should apply the ussual means for making the sail flat.

to Gilo,

Upwind I play the sheet and the tiller, but the tiller not much. I use the sheet to control the heeling angle and the tiller to profit from the gust in pointing higher to the mean wind direction. I try not to force the boat in a direction, just let it go and give gentle corrections. I think that is the way you described your sailing style as well, and I think it is the right way to do it.
Guess the F18 is simply the faster boat (longer, larger, high mast, daggerboard?), you sailed yours better, but size matters... Just my 2 cent.

btw I really like to discuss sail trim in this forum, better than any book.

Cheers,

Klaus

Thanks Matt and Klaus.

In the past I had the habit only to steer in gusts (also in gusts where the wind angle remained the same). It's a lot more exhausting to to the other thing! :-)

I'm sure it's al about sea condition, how hard the gusts are, .... how you react, but this gives at least a rule of thumb to start from.

This is the first daggerboard cat I have and building pressure is a lot different from doing that with a daggerless cat. Therefore these discussion are very interesting to me.

Mike,

The thing I personally feel very good is when you are too far back on the boat sailing downwind. You can really feel the drag and in a way you feel the power without any result. (I'm not sure if this is clear what I mean).

Can't wait to go out next weekend!

Gill

I understand what you are saying. at least I think I do.


Mike

Mike,

I like to think of having the telltales streaming horizontally as "footing" mode (best speed) and lifting 45 deg as "pointing" mode (often best VMG).

Are you referring to only the jib telltales? or would this be applicable to a uni mainsail as well?

You guys have confused me....

I think I'll just drive the boat.


Mike

tback,

I have as good as nil experience with uni-rigs (yet). Intuitively I would say the same principle should apply, but better ask the A-cat guys for verification. Please note that sea-state and other variables will have a major impact on which "mode" gives better VMG to windward.

Best idea there is I think

???????

If your jib is not trimmed correctly then it can not be used as a guide to sail from.

The only time we "untrim" the jib is when we have maxed out the downhaul and still need to depower. Then I make sure the traveler is out and the jib is just sheeted to keep shape. It is out of the way and not adding too much power at this point and the slot is open but it still helps to keep the nose down and driving. Then sail off the main tells for wind dirrection.

Sailing off the main is more difficult to read IMO, but at that point we are more worried about keeping the pointy end up than being able to read every little shift and gust.