How to use the Traveler.

What is the Traveler?

The traveler is a track with an adjustable car to which the mainsail sheet is attached. By sliding the traveler car to port or starboard, the position of the boom is changed without changing the length of the mainsail sheet. In other words, the traveler controls the boom’s angle to the center line and the twist of the mainsail.

Traveler

The traveler position affects the boat’s helm and can produce lee helm, weather helm or balance. Remember, that when trimming sails, your goal is to minimize rudder movement and keep it within a 0-5 degree band.

A primary use of the traveler is to keep the boom centered when sailing close-hauled. Because the mainsheet tackle covers a span between the boom and the boat attachment, the boom will move to leeward no matter how tight the mainsheet is sheeted in. Moving the traveler car slightly upwind when sailing close-hauled can bring the boom back over the center line to gain the most power from the mainsail. Easing the traveler is preferable to easing the sheet or vang, as pointing ability is more easily maintained.

Be careful not to bring the boom to windward of the center line, however. This causes a loss of power.

Trimming with the Traveler.

Generally, with increasing wind, the traveler should be moved from the center line to leeward until the main just luffs slightly in the parts near the mast. In lighter air, move the traveler to windward without having the boom cross the center line. Please note that there are exceptions to this, especially when racing.

Moving the traveler to windward also reduces boat heel and weather helm, the tendency of most sailboats to turn toward the wind with a gust. With the traveler in this position, you need less rudder angle to stay on course, it is easier to steer and boat speed should increase. As mentioned above, if you are sailing with a rudder angle of more that 5°, you are sailing “with the handbrake on”.

Beating and close reaching: Move traveler to adjust the mainsail’s angle to the wind.

Broad reach and running: Use the vang before easing the sheet and move the traveler as far as possible to leeward.

Reminder

To achieve optimum trim, there are four basic adjustments:

1. Adjust twist with the mainsheet/vang tension.
2. Adjust sail depth with mast bend and outhaul.
3. Adjust draft position with main halyard.
4. Adjust helm balance with traveler position.

As usual, go out and play with your adjustments as all boats are different and need to be adjusted accordingly.

Sail Power

Sail power is controlled by three main power sources. Only when you reach the optimum mix of all three will you achieve proper trim. The three sources are: Angle of Attack, Shape and Twist.

Angle of Attack
This is the angle at which the wind hits the sail. When the sails are luffing, you have a zero angle. To increase the angle of attack and the power, trim in the sails, move the main traveler to windward, pull the jib lead inboard , or bear away.

Shape
Depth is the amount of curvature (otherwise known as camber) in a sail. It is measured as a proportion of the distance from luff to leech. A mainsail with a maximum depth (draft) of 10% is a flat sail, while a draft of 15% would mean a deep or full main.
A deep sail provides more power for punching through waves while a flatter sail creates less drag. A flatter sail also creates less drag, is faster in smooth water, and also creates a wider angle of attack for pointer closer. A flatter shape is better in heavy air when a boat is overpowered.

A sail can be controlled by the amount of depth as well as its position. The usual goal is to put the deepest draft about 40-45% of the way aft from luff to leech in a mainsail and 30-40% aft for the jib. Moving draft forward makes for less drag and more forgiving steering in waves. However, moving draft aft enables higher pointing.

Twist
A sail with little twist is more powerful than a sail with lots of twist. You can identify a better twist by noting a closed upper leech that is nearly parallel to the lower leech. Too much twist with power spilling aloft will be seen by an opening at the upper leech. Because the wind is stronger aloft, it is usually necessary to have some twist.  This will allow the apparent wind angle more open near the top of the sail than down low.

Should you need to depower a sail, ease the sheet to increase twist or by flattening. Easing the sheet is preferred in a chop, while flattening is better in smooth water.

Boom Vang

A boom vang (also known as a kicking strap) is a line or piston system on a sailboat used to exert downward force on the boom and thus control the shape of the sail. Boom vang will compensate for a change in sail shape as the mainsail is let out or eased and will control twist on a reach or run.

The vang typically runs from the base of the mast to a point about a third of the way out the boom. A line based boom vang usually includes some type of pulley system due to the great force necessary to change the height of the boom while a boat is under sail. On larger sailboats, vang is most often a hydraulic piston controlled by manual or electric hydraulic pumps.

So, let’s take a look at how to use boom vang for sail shape. The boom vang governs the boom’s vertical angle. When it is tightened, it will reduce the twist of the mainsail. When it is loosened, it will tend to twist the sail, causing the upper area of the sail to be let out in relation to the lower area. Telltales on the mainsail’s leech (back edge of the sail) will guide you in adjusting the twist of your sail.

Check the telltales (especially the top one) to determine if they are streaming aft more than 50% of the time. If not, this is a good indication that you need to adjust your boom vang tension. If unsure, test it by loosening the boom vang until the top area of the mainsail or telltales start to luff. Then, tighten the boom vang until the luffing stops and the telltales are streaming backward.

Anytime you play with the mainsail sheet, the twist of the sail may change. Make sure to readjust the vang if you notice an undesirable twist. If you wish to keep the shape of your mainsail, use the traveler rather than the mainsheet. Also remember that sail shape is maintained by using all three lines: the mainsail sheet, the traveler and the boom vang.

General Guidelines

Your telltales (especially at the top of the mainsail) should be streaming aft most of the time.

Light air: be careful not to tighten the boom vang too much.

Heavier air: tighten the boom vang until the top batten in the mainsail is approximately parallel to the boom.

Next we will cover traveler adjustment and playing with the mainsheet to achieve optimum mainsail shape.

Parts of the Main Sail