Hiya all - I'm 51, with some sailing experience, and recently purchased a 2004 NACRA F18 catamaran. My crew is a lady, colleague and friend, who has some experience in racing a J24. Of course she's learning now what speed is...

We recently entered our first raid, a 3-day, 70 nm coastal race along the ionian shoreline, from Policoro to Porto Cesareo, in southern Italy. Very nice experience by the way.

Anyway, while I find helming quite easy - or at least quite logical - when going to widward, I still do not understand what happens when sailing under jennaker. After reading some books, I learned that the idea is to luff as much as possible under jennaker, and when the sail starts to luff, bear away to refill it. And again and again. But this does not work very well: when I bear away, my bows have to rotate to leeward a fair amount of degrees before the hull comes down... so I think I'm doing something wrong.

Questions: under jennaker, what is the best strategy to keep the windward hull from raising too much? Bear away AND ease sheets? Should I ease off the main sheet or, as other suggest, should I better ease off the traveler?

Thanks all!

are you sure its a Jennaker and not a Spinnaker on a F18? My 5.5 is VERY close the the f18 box rules but i have centerboards so my response is what works for me:

i found the spinnaker took me a few dozen times to understand and work.

you MUST be careful about easing the main at all with a spin (as it acts as a back-stay keeping your mast together) and i am cautious with the traveler for the same reason.

ALL my speed and power comes with the spin sheets and helm, not at all from the mainsheet.

If your bows are popping up a lot, many people suggest you raise your dagger boards. if you are just flying the hull to much, your are steering to much upwind... and your spin (or jenn) is not sheeted in enough

I find heating up (sheeting the spin out a little) and heading upwind a bit.... then with a slight spill off (fall off the wind) while playing with the spin is the best method to gain and increase speed on my 5.5

Lets see, you are sailing the Ionian coastline with a lady on the wire and you want to go fast. Is she attractive? If so I wouldn't worry to much. Just enjoy the scenery.

--
Nacra 5.2
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Sure it's a jennaker, as specified by the class rules.
And sure she's attractive... good suggestion btw

Whats that old saying? Something about it don't count unless
you got pictures?



;)

Quote

Sure it's a jennaker, as specified by the class rules

Unless the "international rules" posted on the NAf18 site differ... the F18 International rules state: (http://www.naf18.com/word…04/F182010_CR_200410.pdf)


C.10 SAILS
C.10.1 LIMITATIONS
(a) The sail plan shall consist of 1 mainsail, 1 jib, 1 spinnaker which shall be
carried aboard.

C.10.4 SPINNAKER
(a) USE
(1) The sail shall be set between the mast and the bowsprit.




G.5 SPINNAKER
G.5.1 MATERIALS
(a) The ply fibres shall consist only of nylon or polyester materials as detailed
in Spinnaker Sailcloth Appendix.
(b) Sail reinforcement shall comply with Spinnaker Sailcloth Appendix.



(e) The area and the dimensions of the spinnaker (SL1, SL2, SMG, SF) shall
be written in an indelible manner near the starboard tack.
G.5.3 DIMENSIONS
Minimum Maximum
Sail area (Small Spinnaker) - 19 m2
Sail area (Large Spinnaker) - 21 m2
Ratio of half width / foot length 75% -
Effective Date: 26 April 2010
Published Date: 20 April 2010

Well, I guess it's a matter of terminology. A gennaker is an asymmetrical spinnaker... there's no spinnaker pole on an F18, as the gennaker uses the bowsprit.

This is a picture of my current boat (not yet mine at that time) taken during the 2009 Italians. How would you call that sail: a gennaker or a spinnaker?

http://www.formula18.it/p…ight_FP_2243%20copia.jpg

And take a look to what a reputable sailmaker says:

http://www.ullmansails.co.uk/index.php?p=1_32



edited by: gpb, Jul 29, 2010 - 03:47 PM

gpb

Well, I guess it's a matter of terminology. A gennaker is an asymmetrical spinnaker... there's no spinnaker pole on an F18, as the gennaker uses the bowsprit.

Absolutely a matter of terms. Around here (USA) we've always referred to that sail as a Spinnaker and the pole as a spinnaker pole. I can see why it would be called a gennaker or screacher especially by sport boat sailors where they might have both a spinnaker (launched from a bag and tacked to a moving pole) and also a gennaker tacked to a bowsprit.

The things on beacchats are possibly "extreme gennakers" or just well behaved spinnakers.

Hopefully we get some other spin/gen experts to give advice about sheeting these things. I know that everything is kind of backwards as far as reactions, and the boats go so fast and develop so much apparent wind that that changes things too.


--
Damon Linkous
1992 Hobie 18
Memphis, TN

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gpb

Hiya all

Oh, and welcome to the site!

--
Damon Linkous
1992 Hobie 18
Memphis, TN

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Alright, now that we know you are talking about spinnakers:

General rule: bear away, ease the spin sheet, flatten the boat, then trim the sheet.

Likely problem: you are heading up too much.

Suggestions: Some people read the telltails on the luff of the spinnaker and keep them flowing. I go by feel. You should be able to keep the sail flowing nicely, very rarely luffing, and in moderate to heavy air you keep the hull flying 99.99% of the time (the pros are able to keep the hull airborne for >25 miles at a time!!!). If you need to de-power, crank on the downhaul, blow the mast rotator and start dropping traveler. NEVER EVER let off on the mainsheet, as it is serving as your backstay. You might get away with an inch, but nothing more and even this can be dangerous. Also, you mentioned distance racing. Obviously heading to where you are trying to go is of utmost importance; during the Tybee 500, if we are trying to lay the beach with the spin up, and your traveller is already dropped fully, you can put both the driver and the crew on the trap wires. This is risky and not neccesarily the fastest point of sail (on the N20, on an F-18 its better), but it might get you to the beach 1 minute ahead of the next boat!

-Sam Carter
N20 USA 1001
Team Velocity Sailing



edited by: samc99us, Jul 30, 2010 - 11:58 AM

samc99us

during the Tybee 500, if we are trying to lay the beach with the spin up, and your traveller is already dropped fully, you can put both the driver and the crew on the trap wires. This is risky and not neccesarily the fastest point of sail (on the N20, on an F-18 its better), but it might get you to the beach 1 minute ahead of the next boat!

-Sam Carter
N20 USA 1001
Team Velocity Sailing

Hello Sam, welcome to TheBeachcats.com good to see you here, the The Tybee was awesome and I had a great time hanging out with you rock stars.


--
Damon Linkous
1992 Hobie 18
Memphis, TN

How To Create Your Signature

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Thanks all for the great replies. Btw, here in Europe, at least in the F18 world, that sail tacked to the bowsprit is referred to as a gennaker: a spinnaker is the symmetrical one, i.e. the one tacked to a movable pole.

no kidding damon, you went from roving reporter to just roving!!!

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bill harris
hattiesburg, mississippi
prindle 16- "BLUE RIBBON"
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Sorry for the delay... here's a recent (1 day old) picture of my crew (with her permission)

ButchG

Whats that old saying? Something about it don't count unless you got pictures?

Edited by gpb on Nov 01, 2010 - 03:04 PM.