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-   -   Sailing downwind is much harder than sailing upwind. (http://www.sailnet.com/forums/seamanship-navigation/66837-sailing-downwind-much-harder-than-sailing-upwind.html)

lydanynom 07-28-2010 01:22 PM

Sailing downwind is much harder than sailing upwind.
 
Am I the only one who thinks this?

I am at the one-year anniversary of owning my first sailboat, and I have been working hard to learn as much as I can to become a somewhat competent sailor. I've been trying to get 15 to 20 hours a week of sailing in, usually in the form of two 8 to 10 hour days on the water. Since I sail primarily on a relatively small lake with lots of power boaters and crazy, twisty winds, I have been getting a good workout in tacking, gybing and making way on all points of sail.

So, okay, just wanted to get it established that I am a newbie but not totally clueless at this point.

There was a thread somewhere recently ripping on people who motor upwind, as if beating was a huge challenge, and people in general always seem to talk and act as if sailing close to the wind a tough thing to do. I have found it to be the easiest point of sail of all. I crank the jib or genny (I have a working jib and 130 genoa) in as close as it will go, head up until the telltales are looking good, tweak the main (backstay, vang, cunningham), and that's that. After that it is just steering to the wind. Maybe playing the mainsheet a bit if it is gusty. I know I am not ready to run with the racers or anything, but there are 4 or 5 similarly-sized trailerable keelboats on this lake and I tend to pass them on a beat, so I figure I must be at least somewhat getting the hang of it.

I'm kind of drifting off my point, though, which is that when close hauled it seems really simple and obvious to me how to trim the sails and when to head up or fall off on the helm. The telltales and the shape of the sails themselves are dead easy to read and it is simple to understand what controls to use when they don't look like they should.

When broad reaching, it is black magic as far as I can tell. I have several well-recommended books on sail trim and (leaving aside for the moment the facts that they sometimes contradict each other and that they are all written with a mastehead rather than a fractional rig in mind) I understand the theoretical aspects of what I want to do, but I have an amazingly tough time getting enough feedback from the wind, waves and sails to actually make it happen.

Is it just me?

jcalvinmarks 07-28-2010 03:08 PM

I'm probably in about the same situation as you, except I wish I could get 15 hours a week sailing. I'm lucking to get one good full Saturday, and usually only half to 3/4 of it even then.

First, as to why people choose to motor upwind, I think it has less to do with the difficulty in trimming the sails, and more to do with the fact that you're sailing a much longer distance to cover the same VMG, you're having to do more work, tacking the sails every time you change tacks, you're heeled over, depending on the boat and the wind, anywhere from 10 to 30, and it's generally a longer, more laborious, less comfortable way to get where you're going. If you're out there for the thrill of sailing, then that's part of the experience. But if you've got somewhere you're trying to go, then it may be easier to fire up the motor.

Once you sail lower than a beam reach, the feedback you get from the telltales becomes useless. The sails are less like wings and more like big foils, catching as much wind as possible.

I've taken the approach -- and for God's sake take this only for what it's worth and not a bit more -- that below a beam reach the objective of sail trim is to present as large a surface area to the wind as possible. Tighten the outhaul, vang (if equipped, which mine isn't) and cunningham on the main to take out the belly of the sail, and ease the jib until it luffs, then trim it in a bit. If you go low enough, a whisker pole to put the jib/genoa out goosewinged is even better.

lydanynom 07-28-2010 03:28 PM

Quote:

Originally Posted by jcalvinmarks (Post 626476)
The sails are less like wings and more like big foils, catching as much wind as possible.

Foil is a synonym for wing, so I don't think that's the word you want, but I get what you mean.

Quote:

I've taken the approach -- and for God's sake take this only for what it's worth and not a bit more -- that below a beam reach the objective of sail trim is to present as large a surface area to the wind as possible. Tighten the outhaul, vang (if equipped, which mine isn't) and cunningham on the main to take out the belly of the sail, and ease the jib until it luffs, then trim it in a bit. If you go low enough, a whisker pole to put the jib/genoa out goosewinged is even better.
Yeah, it is the lack of feedback from the telltales and generally close to zero apparent wind that makes it so hard for me to figure out the right thing to do to optimize.

I don't think you want the belly out of the sail. At least, I have been easing outhaul, cunningham and backstay as I turn downwind, and only keeping enough vang on to hold the boom down without putting tons of tension on the leech.

I have tried running straight downwind with the headsail whiskered out, but there really are a lot of big wind shifts as you sail around this little lake so it is a little stressful trying to avoid a bad crash gybe.

sailordave 07-28-2010 03:33 PM

Well, I don't have a lot of time to expound... but even broad reaching (since the OP mentions this in the last parag.) you should still be able to get some use out of the tales. More importantly I have found that people tend not to ease the sails as much as they should. Actually on most points of sail this is true. So ease the sail out until it's obvious you're losing speed or stalling the sail. And maybe even more than going upwind it's important to keep in mind the effect your AWA has on your VMG. A very slight change in AWA could result in a significant change in VMG. Another case of where a handheld GPS is real handy. (project out a point that is directly downwind from your next mark but several miles beyond. Use that to see what your VMG is b/c if you use the mark you're steering for, your VMG is going to decrease the further left or right you get from a direct course.)
But that's another lesson for another day...
Just keep practicing. I used to take my Laser out on the local reservoir (pre 9/11) beat all the way to the far end and then sail back downwind jibing the WHOLE way to get better at jibing. I mean like 1.25 miles of this every 10-15 seconds!
Not that it did a whole lot of good.... lol

sailordave 07-28-2010 03:36 PM

Quote:

below a beam reach the objective of sail trim is to present as large a surface area to the wind as possible.
No, you don't want to present as much sail area to the wind; that means you're just using the sail as a big barn door. Gotta try to keep some semblance of a sail (foil!)

jcalvinmarks 07-28-2010 03:40 PM

Well, there, you see, that's what I meant by take it for what it's worth. Evidently, not much. I'll shut up now and be a pupil instead. :)

lydanynom 07-28-2010 03:50 PM

Quote:

Originally Posted by sailordave (Post 626479)
More importantly I have found that people tend not to ease the sails as much as they should. Actually on most points of sail this is true. So ease the sail out until it's obvious you're losing speed or stalling the sail. And maybe even more than going upwind it's important to keep in mind the effect your AWA has on your VMG. A very slight change in AWA could result in a significant change in VMG. Another case of where a handheld GPS is real handy. (project out a point that is directly downwind from your next mark but several miles beyond. Use that to see what your VMG is b/c if you use the mark you're steering for, your VMG is going to decrease the further left or right you get from a direct course.)

That's a great suggestion for using the gps to project a point so I can see VMG.

As for sufficiently easing sails downwind, one thing that has me probably tending to err on the side of overtrimmed is the way the main starts getting mashed up against the raked-back spreaders when it is out more than halfway. I've been worried about chafe.

sailak 07-28-2010 04:12 PM

Quote:

Originally Posted by lydanynom (Post 626478)
I don't think you want the belly out of the sail. At least, I have been easing outhaul, cunningham and backstay as I turn downwind, and only keeping enough vang on to hold the boom down without putting tons of tension on the leech.

New as well but...

Ease the cunningham, outhaul and halyard when running. You want the sail as "full" as possible to "catch" as much air as you can. Use the vang to take the twist out.

smackdaddy 07-28-2010 04:16 PM

Quote:

Originally Posted by lydanynom (Post 626491)
That's a great suggestion for using the gps to project a point so I can see VMG.

As for sufficiently easing sails downwind, one thing that has me probably tending to err on the side of overtrimmed is the way the main starts getting mashed up against the raked-back spreaders when it is out more than halfway. I've been worried about chafe.

Better yet, set up a Global Regatta course for your area (unless there already is one). Racing on our short course in Lake Travis has really helped me learn quite a bit in a short time.

http://www.sailnet.com/forums/racing...ssible-23.html

Lots of fun. But I need to sail faster if I'm going to catch those Chessie dudes.

bobmcgov 07-28-2010 04:25 PM

Hi, Lyd! *waves* I agree, sailing downwind means sail trim, boat trim, and rudder feedback are less obvious than beating. Your sails transition from lifting foils to drag bodies, but not all at once. Little-known fact: Even a symmetrical spinnaker is a lifting foil, along its windward edge and maybe 1/3 of its girth. Also along its foot. The rest of it is pure drag.

Likewise the main and jib. Around a broad reach, it becomes difficult to keep flow attached all the way to the leech. But you should still try to keep the front portion of your sails lifting, and that means tweaking attack angle. Watch the tells on your jib and the luff on your main; the main will probably give up the ghost first, because the oval mast section will develop turbulence behind it. That's why they invented rotating masts.:D

Try shoving your jib leads as far forward as you can. Refresh my memory -- even on the Mk2, the working jib sheets inside the shrouds, true? You could run a second set of sheets to the genoa tracks, or in light air we sometimes hand-fly the jib outside the shrouds from a broad to a deep reach. The farther you can get that clew away from the centerline, the farther back on your jib the airflow will stay attached.

Your apparent wind will seem all over the place as puffs, surfing, and boat speed shift it thru 60 degrees or more. Trim for the average and steer small. Bag out the main (ease outhaul and downhaul), and then vang the boom. Maybe give a tug on your leech line, if you have one. The combination will curl the leech in while keeping max draft on the sail. Our SJ21s have no roach at all on the mainsail, so you don't need to vang too hard to prevent the top from twisting off. By vanging, you can ease the boom out farther without the sail hitting the spreaders -- and as Sailordave says, you want that boom out as far as you can get it, to milk lift as long as possible.

Other interesting quirks of the SJ21 below a beam reach: In light air, get everyone back and induce some heel -- to leeward near a beam reach, to windward DDW (may need a preventer for that.) Remember, this boat is just a big dinghy and wants to be sailed like one.:) In following waves, especially swells, get the weight aft to keep the rudder in the water. In middling-to high winds and small waves, sail the boat flat flat flat with the weight centered. I've had ours cooking along a deep reach (~150 TWA) at 7.8kts sustained -- not quite planing, but well above hull speed and with the apparent coming right over the beam. At those speeds, the stern begins to squat like crazy: you'll hear a noise like a sump pump sucking air. That's why you need to move crew weight more forward as boat speed increases. It won't ever break loose entirely, but you'll gain from raising the transom out of hole.

I confess I'd love to try broad reaching with the keel up, but I'm too chicken.:D


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