Vanguard 15 Tuning Guide

Tuning and Sail Trim Manual
Click on a topic, or simply scroll the page to read through the guide

Setting Up the Rig: Mast Step

Setting Up the Rig: Rake

Setting Up the Rig: Tension

Setting Up the Jib

Setting Up the Main

Your Vanguard 15 sails are designed and built by North Sails to be consistent, easy to trim, and durable. If you are looking for a quick, no-brainer setup, just read the "quick tips" below. If you want to experiment with some different settings, it's all in "the details."

Setting Up the Rig: Mast Step

QUICK TIP: We recommend that, in most conditions, the mast be positioned so the forward edge of the mast is 1/2" behind the front of the mast step channel.

THE DETAILS: If you want to experiment with mast step position, try moving the step 1" aft in light and lumpy conditions, and 1" forward in flat water or windy conditions. The explanation of why this works is a bit complicated, but if you're curious, here's why:

The position of the mast step has an effect on mast bend, both fore-and-aft and sideways. As the mast is moved forward, it becomes stiffer fore-and-aft. And as it is moved forward the mast will sag less to leeward at the spreaders.

This is caused by the length of the V15's spreaders, which are a bit on the long side. As a result they tend to push the mast to leeward slightly as breeze increases or as you trim the mainsheet. This leeward sag makes the mainsail leech tighter, which is OK if you are trimming the mainsheet to point higher, as you might in light to moderate air.

The problem occurs in heavy air--when a tight leech from leeward sag is not fast. By moving the mast forward, the effective length of the spreaders is shortened because the mast is being moved away from the shroud base. As a result, there is less leeward sag, so the mainsail sets up flatter.

There are two other side effects of moving the mast step forward, however. First, the boom hits the shroud earlier as you ease the mainsheet -- the result is that the boom cannot go as far out downwind. Second, the spreaders of the V15 are pinned to prevent swinging, so as you move the mast step forward, the spreaders pull the center of the mast aft -- the effect that the rig becomes harder to bend in a fore-and-aft direction. This is added stiffness is great in heavy air, as helps to provides a firmer forestay. But it means that you need to use a lot of vang tension to bend the mast adequately in those conditions.

In light-to-moderate, choppy conditions, moving the mast step aft can be fast, as it makes the mainsail more powerful. This is because of the increase in leeward sag. It also allows the mainsail a little more freedom to bend fore-and-aft as you play the mainsheet -- again a good thing in those conditions.

Setting Up the Rig: Rake

QUICK TIP: A good all-around rake setting is usually about one-third of the way up from the bottom of the shroud adjusters.

THE DETAILS: Rake is the fore-and-aft tilt of the mast, controlled by the shroud pins, and is an important power adjustment on the V15.

The first step in setting rake is to make sure that the two shrouds are the same length. You can do this two ways. The first way is to take off the spreaders and lay both shrouds against the front of the mast and compare their respective lengths. The second way is to step the mast, attach the shrouds, hoist a tape measure to the masthead on the main halyard, then run it from rail to rail to see if the mast is centered in the boat. It is not unusual for there to be a slight difference in shroud length from side to side, and if so, you can easily correct this by putting one shroud pin a hole higher than the other.

After you have centered the mast and the shrouds are pinned, hoist a tape measure to the masthead again. It's best to pass the main halyard through the loop in the end of the tape measure and tie a stop knot to ensure that the halyard is fully hoisted. Next take the tape measure to the transom, on centerline.

Then put two fingers on the forestay and pull forward lightly -- just hard enough so the slack is pulled out of the shrouds, but no harder (it's best to do this on a calm day) and read where it meets the deck at the transom, on centerline. This measurement is your rake.

Adjust your shroud pins so the measurement reads 21' 8" -- this is your light air setting. On most V15s, this will be approximately in the middle of the chainplate adjuster. As the wind increases, you can depower the boat by lowering the pins to add rake.

The total range in rake, from light air to heavy air is about one foot, or about from the middle to the bottom holes of the shroud adjusters. Lighter crews need to rake more aggressively than heavy crews. For example, a 320 lb crew might not drop down to under 21' feet of rake until the wind is over 20 knots. But a 270 lb crew might be at 20' 8" in only 15 knots.

To understand when you need to rake, you first should know what effect rake has. Increased rake twists and therefore depowers the jib. The effect is the same as moving your jib leads aft (on a boat with adjustable jib leads).

Increased rake also changes the balance of the boat. It adds a bit of weather helm, counteracting the lee helm that would develop when you dump the mainsheet in a puff. As a result, you can still feather the boat into the wind with the mainsheet eased. Rake also counteracts the lee helm that would develop as you raise the centerboard upwind in a breeze (more on that later). All this makes it possible to plane upwind in a strong breeze. Here is a guide for an average V15 crew--about 300 lbs.
Rake settings

0-7 knots
8-11 knots
12-15 knots
16-20 knots
over 20

21' 8"
21' 5"
21' 2"
20' 11"
20' 8"

Setting Up the Rig: Tension

QUICK TIP: Have the lighter member of the crew lean downward with all his or her weight on the jib halyard purchase to tension the rig in light air to moderate air. In moderate to breeze conditions, have the heavier member of the crew lean on the halyard purchase before cleating. Don't pull on the forestay to add additional tension, as this can damage your boat.

THE DETAILS: You rig tension is controlled by how hard you pull on your jib halyard. The tighter your rig, the less your jib luff will sag to leeward. This flattens your jib, and is fast in a breeze. So you need to increase tension as the wind builds.

Here's how to measure rig tension: First set your shrouds to the light air position. Then hoist your jib in calm conditions. Adjust the halyard so the slack is taken out of the shrouds--the same amount of tension as you used to originally measure rake. Put a mark on your mast next to the jib halyard purchase block. Then tension the halyard so the block is 1.5" lower on the mast. This is your minimum amount of tension, and is the mark you should pull the halyard to in light air.

Next, increase your rake to maximum. Again, first set the halyard tension so the shrouds are just taught. Then tension the halyard so the block is 2.5" lower on the mast. Mark the mast. This is your maximum tension, and is the mark you should pull to in heavy air.

If you are so inclined, you can put marks on the mast for all your rake settings, gradually increasing the tension from 1.5" to 2.5" as the wind increases. In practice, most V15 sailors find all those marks cumbersome; instead they simply get used to the "feel" of proper rig tension. To do this, grab the shrouds and try to move them, feeling the tension. Do this onshore, first with your light, 1.5" tension setting, and then with the heavy, 2.5" tension setting. With some practice, you should be able to do this on the water as well.

Another simple way to judge rig tension is to watch your leeward shroud. When sailing upwind, the shroud should be just starting going slack as you are eased and footing. When you trim the mainsheet hard, the shroud should go completely slack.

Setting Up the Jib

QUICK TIP: Put the tack shackle in the aft hole on the stem fitting. Adjust the lashing at the head of the sail so you have just a hint of wrinkles in the luff. Trim the jib sheet so the seam between the two leech battens is pointing straight aft.

THE DETAILS: As mentioned above, the jib sets up best with the tack shackle in the aft-most hole in the stem fitting. As for the luff lashing at the head, setting it for a hint of wrinkles in the luff is correct in most conditions. Only in heavy air should it be tighter -- so tight that there is noticeable tension on the cloth. When a jib is new, the sail is firm enough so you shouldn't have to adjust the luff lashing except in the extremes of wind velocities. However, as it ages, the sail becomes more stretchy, so you may have to adjust your lashing more often.

Jib sheet tension is a critical adjustment on the V15. A basic rule is to look under the boom and sight the battens on the jib leech. After you have set the sheet by sighting up the leech, then hike out and see how that top batten looks through the spreader window.

At max trim, while looking up the leech, the top batten should be pointing straight aft, parallel to centerline in most conditions. This will mean that the bottom batten is hooking slightly to windward. At max ease, the bottom batten should be pointing straight aft, and the top batten angled slightly outboard. The trim between these two tensions is a good, all-around setting.

Some crews like to mark the jib sheet for quick reference. Two marks are put on the sheet, one is 1' 10 1/2" from the center of the clew gromment, the other is 1' 9". In most conditions, you will should be trimming the sheet between both of these marks, using where they exit the cam cleat as a reference.

If you find that you always eased outside of this range to get the battens angled correctly, you probably have too much tension on the luff lashing (luff tension raises the clew height). Also note that the 1995 jib design had a longer leech, and if you have one of these sails, you will have to trim harder than these marks to get the jib battens to align with centerline.

Setting Up the Main

QUICK TIP: Insert the top batten without adding tension. Set the outhaul so the foot curl of the main is nearly touching the boom. Adjust the cunningham and/or main halyard so there are slight wrinkles in the luff of the main. Put the board all the way down, except when you want to plane upwind, then raise it 2-3". Tension the vang until you no longer feel overpowered--this can be a lot of vang upwind in heavy air. Tie the traveler so that, when the bridal is laid aft, the apex on the transom gunwale at centerline.

THE DETAILS: It's easy to overtension the top batten of the main, and doing so will make the top of the main too full. Insert the batten and close the Velcro without adding tension.

Another common mistake is to set the outhaul too loose. The curl of the foot should be nearly touching the boom in most conditions. A more accurate way to measure the outhaul is to put a ruler on top of the boom and measure out horizontally to the body of the mainsail. A good all around setting is to position the body of the mainsail 3.5" off the boom. In light, sloppy conditions, you can ease the outhaul so it is 4.5" off the boom. In heavy air, tighten the outhaul so the foot of the mainsail is 2.5" off the boom.

With a new mainsail, you have to use very little cunningham. But as the sail ages, you will need to apply cunningham tension to pull the draft, or fullness, forward in stronger winds. A basic rule of thumb is to set the cunningham so there are just slight wrinkles in the luff of the mainsail.

A more advanced rule of thumb is to set the cunningham so the point of maximum draft is halfway across the sail from luff to leech in light-to-moderate air. To plane upwind in heavy air requires that you move the draft forward slightly from that position, and this will require more cunningham. In heavy air, there should be no visible luff wrinkles.

Vang tension is perhaps the most critical adjustment on the V15. The vang bends the mast and so has a tremendous effect on mainsail fullness and overall power.

With the mainsail fully hoisted (use a trucker's hitch at the cleat to add purchase, and/or replace the halyard with low stretch rope), take the slack out of the vang without adding any tension. Mark the tail of the vang purchase as it comes out of the cleat.

The total range of vang tension, from light air to heavy air, is 3" of "gross throw." This is the total amount that the entire purchase shortens as you tighten the vang. If you have a 3:1 purchase, this represents 9" of rope being pulled through the vang cleat. Many V15 sailors, especially those sailing with small crews, have opted to increase the purchase in the vang by tying extra loops in the existing rope -- ask any Laser sailor to show you how to do this. Multiply whatever purchase you have on your vang by the "gross throw" adjustments below, and then translate the results to marks on the tail of your vang as it exits the cleat.

Vang Tension

0-7 knots
8-12
13-16
17 plus

0"
1"
2"
3"

One final control is centerboard height. In most conditions upwind, the board is left all of the way down. However, in a strong breeze, you can dump power by raising the board. It is essential that you raise the board if you want to plane upwind.

In winds over 15 knots, it is possible to ease the sheets enough that the boat begins to plane upwind. The boat will point about 5-10 degrees lower, but will sail much faster. Whether you actually get to the weather mark quicker depends on how much wind there is (it's easier the windier it gets) and how adept you are at maintaining height while planing.

Successful upwind planing also requires that the vang be tensioned very hard, the rake be well aft, and the centerboard be raised about 2"-3".

Centerboard Height

0-14 knots
15-16 knots
17-19 knots
20 plus

max down
1" up
2" up
3" up