Sailing is a lot like driving a stick shift car. Road conditions, traffic and weather can cause you to shift up or down. It is the same with sailing – the wind speed and direction plus the wave condition are ever changing. What this means is that if you want to get 100% efficiency from your sail boat you have to “shift your sail trim gears” to compensate for the ever changing conditions. In other words, you just can’t set the trim and forget it. So what adjustments can we make to compensate for the ever changing conditions? One adjustment we can make is steering. You can head up or fall off and see how that movement affects the efficiency of the boat but that only gets you so far. You can also adjust the heel angle by simply moving the crew inboard or outboard. The most important thing you can do is adjust the shape of your sails. This is a bit more complicated but once you understand the function of each sail trim control for the main and jib, this becomes a simple matter. Additionally, you have to know what sail shape is required for each wind speed and point of sail, but we’ll get into that later. Understanding the function of the sail trim controls for the main and jib is the heart of the matter, so lets talk about the function of some of these sail trim controls. Outhaul – this sail trim control induces or reduces draft depth (belly) into the mainsail. It controls the sail shape of the lower 2/3 of the mainsail. Boom Vang - this sail trim control is used to control leech tension. Without it the boom will rise and the mainsail will luff. The amount of tension you apply on the vang depends on the wind sea conditions. Cunningham – this sail trim control performs the same function as the halyard but is easier to use. Its function is to move the draft position forward and aft, again depending on conditions. Jib Halyard – performs the same function as the Cunningham except on the jib. Backstay – its main function is to flatten the mainsail. Fairleads – the absolute most important sail trim control for the jib. The fairleads are used to adjust draft depth, draft position , twist and angle of attack. Traveler – controls angle of attack. Mainsheet and jib sheet – they are used to shape the sails. The above is just a brief outline of the function of the sail trim controls but it is all you’ll need to know to follow this thread. If you would like a detailed explanation take a look at my book “The sail Trim Users Guide” which is available through the ships store. In the next session, I’ll explain how you shift sail trim gears for various conditions – just like you do when your driving a stick shift car. Any questions so far?
