Our black mark on the Halyard, was wrong.
So will try again.
The top of the spin was not visual from the back of the boat.
I recall seeing the purple spin more than the yellow.

Seems loose on the f17, looks good on the blade. but seems like the mainsheet could have been tighter on the blade... but I wasn' there that day, don't know the real conditions (enter any caveat here...). I would think it might (emphasis, might) pull the bows up a little if you let the tack line out on the spin, not halyard (if it is a 2-line set up)

About lifting the bows. How much more "upforce" will the new profile of the sail produce if you let out 20-30 cm of the halyard? (Wouter is going to love this) Well, the short answer is 'not much' as the change in the resultant vector is not very large compared to the forces on the mainsail pushing the bow down. I have not done the math (I dont have that kind of math) but the reports I have found on the topic suggests this.
What I think happens is that the sail flattens when you let out the halyard and it rotates to leeward, thus it generates less power but also less drag.
If it was me going downwind, I would have set the spi with a tighter luff and sheeted the main in more. Then pushed the crew out on trapeze so we could heat up the boat. This from somebody with zero practical F16 sailing experience <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

Do the I17s usually go downwind with the skipper sitting on the hull? I really look forward to start working on my trapeezing skill while sailing under spi!

I think if running uni- stay on the hull. If I were racing solo last weekend, I am not sure I would have trapped downwind. I probably would have for a bit (or maybe if I were really behind) until I went over and then I would have stayed on the hull. 2-up I think one definately should go out on the trap if they know how to move around on the trap and stay attached to the boat more or less. The speed difference is huge and, in my experience, sitting on the hull as far back as possible still has the bows digging in and stopping the boat routinely. Need someone on the wire behind the rear beam to keep the bows up. Once that happens then SWEEET! You can fly! and things are actually more stable.

If you have access to a heated pool, I'd put in a few practice laps. <img src="http://www.catsailor.com/forums/images/graemlins/laugh.gif" alt="" />

If you can sail the boat in it's current state, you dont need a heated pool.



Besides, thanks to the Gulf current we have nice sailing conditions now. Just dont go for a prolonged swim <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" />

I have never seen an F17 sailor trap out on a downwind leg during a buoy race. They are instead staying onboard and sailing deeper............

Plus, I'm guessing by the time you got trapped out you would have lost valuable time. Also, you wouldn't be able to control the main if you needed to use it to sail up closer to the wind for some reason. (like maybe passing on the windward side if the opportunity presented itself)

Tom

I agree with Rolf here.

Set everything rather tight and then slowly head-up to pick up pressure and speed and start snaking , making S-curves to keep the luff hull up.

I found it works best on my boat when I do this hiking out (not trapezing) with my hand only pushing against the tiller arm of the rudder (not the tiller bar or tiller extension). On my boat I can feel the slight changes in pressure on the rudder-tiller and that is enough info for me to tell me whether I need to head up or bare off.

Works for me ; even when it DIDN'T at the GC 2007 <img src="http://www.catsailor.com/forums/images/graemlins/mad.gif" alt="" />

Although it did again during the following NAM-REM distance race. I was way back after the upwind leg and regained alot (close to 8 minutes) during the last halve of the downwinder.

Wouter

Tom,

thanks for the info on the I17s. We discussed this earlier and it seems like we (singlehanded spi cats) might have potential for a fifth gear downwind under spi. When the Musto Skiff guys can drive their boats from the trapeze downwind, we should also be able to do it. I might have to eat those words, but working on it will be fun. <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

PTP,




That is exactly how most of us have experienced it

Just sitting on the hull next to one another is NOT enough in a blow; that is if you want to go fast. The difference between a crew sitting next to the skipper or hanging behind the skipper on the trapeze (even when in toilet stance) is quite significant. If the crew can even get a little further back as you say and stand level with the rearbeam or use even the footstrap then things start to power and speed up alot and the skipper can drive it hard.

My advice is in line with PTP here, get that second person away from hugging the sidestay and on the trapeze when under spinnaker in a blow. When it is reall rough then a little trick my crew and me do is to have her trust her rear foot between the mainbeam and my rear end and have her grap my lifevest with her rear hand. She holds onto the sheet with her forward hand and I help her trim it. Once trimmed right I handle everything by steering. Then I'm not looking anywhere specific and just drive it by feel.

Only problem for the crew is that he or she one needs to trust the skipper to have a steady hand on the tiller; if your skipper is nervous and twichy on the tiller then by Gawd I refuse to go out on the wire under spinnaker ! Will feel like some stunt man in an action movie trying to hang on on the roof of a car while the bad guy is trying to shake him off !

Wouter

I can be pretty twitchy driving down until I get a groove going- that is why my crew needs to be experienced in "holding" on when out on the trap. When I crew on an HT, I have my foot in the strap (same place as on the F16) and my aft hand on the transom!

Tom,

Interesting, I would wire my Inter 17 down wind above about 10kts and below about 20 and found it to be much faster VMG, BUT, I do sail on a lake with flat water.

I also agree that if the Musto Skiff boys and Girls can do it, we should too!

I think the F17 would fly downwind on the trap! I think it has more bouyancy up front than an F16 so it would probably be easier to do (but then again, maybe the gains are less then also). I don't think Fad recommends it, but he is always at the front during a race anyway so he doesn't have to haul butt to try to make up ground for stupid mistakes (like my famous tendency to triple tack within 50 yds of a mark or the finish!!!).
maybe there are other reasons he doesn't like trapping out downwind, like ...well... I can't say it!

T foils on the Stealth make it easier than the Inter 17, and the 17 was well mannered up to about 25kts.

Trapping out downwind (while buoy racing) was tried back in the day, but it just didn't work. The guys that did it found themselves losing too much ground to the rest of the fleet not to mention when they tried to jibe. The boat(F17) will scream downwind in about 16 knots and up anyway. You don't need to trap out. Just sit as far back and to the side as possible and go low when the thing wants to pitchpole.

Now distance racing is another story.


Tom

I'm really interested in this; How big were the courses?

We sail on about 1.25 - 1.5 mile W/L

Roughly 2mi (~1.98mi) W-L each day

I haven't sailed an F17 in almost two years, but don't you think if it was so fast the guys sailing them at Midwinters would have been doing it if it worked so well............??

Tom

But what is the real reason they weren't out on the wire?
The reason I bring it up is that it is clearly faster to trap out downwind for Me on my Blade. Sitting on the tramp as far back as possible still has the bows dig in too much for me. Maybe this is only me, but the difference between sitting at the rear beam and trapping AT or Behind the rear beam is huge interms of the way the boat drives and flies. The VMG issue can be debated of course though. I don't have a lot of data to support it but I feel that I would get better VMG downwind- including the gybing issues- out on the wire when racing solo. I think a lot of the issue with driving solo is to not get overwhelmed and go over especially in any decent wind. It makes no sense to trap downwind in a race if you are guaranteed to capsize of course.
Some math guys could chime in but the speed difference, IMO, is probably 5 kn(?) or so sitting vs trapping. Lets say you have to run 10degrees higher. Who wins? I hit 18.5-19 kn routinely last week sailing two up with someone on the wire behind me in 15kn (or so) winds

Tback and Tshan... what is your take on this? Do you not trap out downwind because you believe it to be faster or is it mainly a concern about capsizing? I think it is perfectly acceptable to race and not go out on the wire solo. But is it faster?
Hell, I think this has been discussed before... but I don't remember.

Like I said, when the thing wants to pitchpole go low or deep or whatever it is you wanna call it.

If I had it to do over again(when I was first learning the beginner stuff), I think I would just watch the first race at a regatta like Midwinters and see how it's done. The guys that have some time on the tiller don't usually let the bows dig in in the first place. They have already seen the puff coming and are ready to head low even before it arrives.....

Tom