Flying Scot Tuning Guide

Current as of: 7/2008

A basic guide to tuning your rig, trimming your jib, main, and spinnaker, and working your centerboard.

 

RIG TUNE:

            Besides sail trim, the most important thing to do is to make sure your rig is correctly tuned. Step one is the measure mast rake. To do this, tie the loose end of a tape measure to the main halyard and raise it until the shackle is up against the halyard sheave. Bring the tape measure back to the stern, where the transom meets the rear deck. The measurement from the top of the mast to this point should be between 28’ 4” and 28’ 5 ½”.  The next step is to measure the “slop”. Do this by pushing the mast forward until the shrouds prevent it from going any further and measure at the same point on the transom. This measurement should be between 2” – 5”. In light to moderate winds, you want more slop (closer to 5”) and in heavier winds you want to have closer to 2” of slop. Once all this is done, it is always a good idea to check your shrouds. Make sure they are the same length (measuring with the tape still hoisted up) to ensure that the mast is not leaning to one side and is straight up.  

SAIL TRIM:

I.                   Jib:

1.      Halyard: The first step in trimming the jib is to get proper halyard tension. You do not want it to be super tight. In fact, just a small bit of “crow’s feet” wrinkles between the snaps is perfect. If the wind starts to build, it will be necessary to tighten the halyard, making the wrinkles disappear, especially if you become overpowered.

2.      Jib Leads: The jib leads should be all the way forward on the track for most conditions. Only in very heavy winds, or when you are overpowered, do you want to move the leads all the way aft on the track.

3.      Weather Sheeting: The jib leads are a bit too far outboard, so to compensate it is common to weather-sheet (tighten the lazy jib sheet). This pulls the clew closer to the centerline of the boat. You do not want to pull the weather sheet very tight, only enough to bring the clew to the middle of the seat. You do not want to weather sheet when the wind is extremely light and the jib is just hanging, or when the wind is extremely heavy or you are overpowered.

4.      Tying the Sheets: Tie the jib sheets on with an overhand knot, keeping the knot between 6” to 10” away from the clew. This keeps the pull from the sheet going across instead of down.

5.      Going Upwind: Trimming for upwind sailing is generally a three step process. First, you want to pull the leeward sheet until the foot of the jib is smooth. Then, trim the weather sheet (previous section). The foot will naturally curl up once the weather sheet is trimmed. After that, you want to tighten up the leeward sheet, flattening out the foot just a bit, but keeping a good deal of foot curve, and making sure that the top batten is straight back, basically parallel to the center line of the boat. If you hit chop or head into a lull, let the leeward sheet out slightly so that the top batten is at about a 15 degree outboard of the centerline. Once you get through the chop/lull, re-trim so that the batten is nearly parallel again. You want to keep the tell-tale that is on the top batten flying straight back AT ALL TIMES. This is the main gauge for jib trim. Keep in mind that in extremely light or heavy winds, the windward sheet should not be trimmed at all.

6.      Going Downwind: The jib generally stays up when sailing off the wind, though, in very light wind, bringing it down helps the spinnaker breathe a bit better. This can be very fast, but be sure to get the jib back up quickly enough to round the leeward mark. Trimming the jib downwind is basic. Trim it just enough to keep it from flogging about, but no more. After that, try not to mess with it too much. In comparison to the flying the spinnaker properly, it is of little consequence.

II.                Main:

1.      Halyard/Cunningham: When pulling up the main halyard, do not rely on just that to get the wrinkles out of the luff. This is especially important in light air. When tightening the cunningham, pull it until there are just slight wrinkles in the lower third of the sail. If the wind builds and you are overpowered, it may be necessary to use more cunningham, but generally you shouldn’t need to touch it once you get the proper wrinkles in the sail. It is better to be a little too loose than a little too tight.

2.      Outhaul: Tightening the outhaul helps to depower the mainsail. Generally, upwind, there should be about a 1 ½” to 2” wrinkle between the footshelf seam and the boom. If the winds are particularly light, or the seas are choppy, ease the outhaul so that the wrinkle is between 2” and 3”. Going downwind, it should be even more eased than that, making a 3”-4” wrinkle. As the wind builds, you want to keep tightening the outhaul and pulling out the foot shelf. In very heavy winds (over 15 mph), it should be pulled all the way tight, with a hard crease from the tack to the clew in the foot shelf.

3.      Boom Vang: Going downwind, vang tension is the most helpful. You want the vang eased almost all the way out, leaving just enough tension to keep the boom down and support the leech. A good guide is to keep the boom parallel with the top batten of the main. Keep an eye on the tell-tale, also. Keep it flying! When going upwind, keep the vang just tight enough to prevent bouncing in light air, and tighten as the wind picks up. Be careful, though! Flying Scot booms have been known to break when rounding the weather mark, so be sure to loosen the vang before you head downwind!

4.      Going Upwind: The main sheet should be trimmed so that the upper batten is parallel to the boom. In light air, it is ok to ease the sheet so the batten angles leeward just a bit (about 5 degrees). In super light air, or drifting conditions, trimming the sheet in until the top batten is centerlined may help. In mid-range wind conditions, once the boat is up to speed, trimming the main in until the batten is angled just to weather of the boom is a big speed bonus. In very heavy wind, you want to, again, ease out the main sheet until the top batten is a few degrees to lee of the boom.

5.      Going Downwind:  Main sheet trim going downwind is simple. You want to let it out until it starts luffing and then sheet in just until it stops. Once that is done, use the vang to keep the top batten parallel with the boom.

III.             Spinnaker 

1.      Afterguy Trim: The best way to trim the afterguy is to make sure that the spinnaker pole is roughly at a 90 degree angle to the wind, about as far back as the wind will let you put it. Keep an eye on it – it should be moving with every change in the wind.

2.      Sheet Trim: Trim the sheet with smooth motions. Try not to jerk it in and out. You want the spinnaker trimmed so that there is a constant 6” – 12”curl in the luff. Be sure to not over trim it (you can tell if you have when there is no curl in the luff) or keep the sheet still. It should be moving in and out of your hands continuously to keep that curl going in the luff.

3.      Topping Lift: Optimally, the clews of the spinnaker should be even at all times. Use the topping lift to move the pole up or down to make that happen.

4.      Halyard: Keep the head of the spinnaker about 6” away from the top of the mast. Many people tie a knot in the halyard to make sure they have put some distance between the sheave and the head of the sail.

IV.             Centerboard

1.      Going Upwind: Keep the centerboard down at all times when going upwind, in any condition. Doing otherwise will severely affect your steering and greatens the possibility of a capsize.

2.      Going Downwind: When sailing on a run or broad reach, you can pull the board up about Ύ of the way. You want to make sure you keep the helm balanced and the boat pretty flat.