• Admin
• Jul 17, 2024
• Sailing

How to Trim The Gib

As with the Mainsail, There Are Three Main Ways That the Genoa Trimmer Can Ensure Their Sail Is Optimized

The trimmer will add power by trimming the sail in or reduce power by easing the sail. In addition, they will control the draft and the twist of the sail.

Overall Genoa Shape

The aim of setting the genoa is to create a smooth shape parallel to the mainsail. This will create a lovely slot that speeds the airflow across the leeward side of the mainsail to its leech. A slight backwind on the mainsail is acceptable. In light winds, the sheet will be eased slightly (the leech will be quite far from the top spreader), and as the wind builds, it will be trimmed in until the leech is virtually touching the top spreader.

Using the Genoa Leads

The genoa leads should also be set so the genoa has an even shape. This should result in the top telltales breaking first and then the rest breaking in turn toward the foot of the sail. To add power to the genoa (e.g., to cut through waves), move the leads forward to give the foot of the sail more draft. When the lead is all the way forward, the telltales will break simultaneously. In smoother water, create a flatter sail by moving the leads aft, allowing the sheets to be trimmed harder and enabling the boat to point higher.

In heavy winds, moving the lead aft adds twist, spilling wind from the top of the genoa.

Controlling Draft

The trimmer adjusts the shape of the sail using the sheet and the lead position. These controls allow for either a deeper draft (for more power) or a flatter draft (for less drag).

Controlling Twist

The trimmer controls the amount of twist in the sail by using the sheet. As the sheet is trimmed in, the angle of attack changes, and when it is hard in, the clew of the sail is pulled down, changing the amount of twist. The lead position can also be used to adjust twist. A closed leech keeps the power in the sail, whereas twist spills power from the sail.

Headsail Selection

A good crew will know which mainsail will be required before it is requested. This knowledge comes from regular practice on the boat and the creation of a graph to show which headsail is suitable for various wind speeds and sea states.