Basic Sail Controls

with Koralina

There are plenty of lines on a boat and none of them useless. Knowing what to pull when can save you hassle and stress in the right situation. Today we’re discussing the in’s and out’s of your basic Sail Controls.

When it comes to remembering all your options for sail controls I like the acronym:
Our Boats Can Happily Sail The British-Virgins
Outhaul, Backstay, Cunningham, Halyards, Sheets, Traveler, Boom-Vang
Conveniently they’re even in the order of importance and usability

I’ve included this image to help us identify and locate each sail control

sail controls

Let’s start from the beginning

Outhaul- The Outhaul is attached to the clew (aft corner) of the mainsail then runs through the boom and comes out of the boom about a third of the way back from the mast.
Function: The Outhaul affects the depth of the sail (draft). When tightened it flattens the
bottom of the sail and makes the boat easier to handle in building breeze.

Backstay- The Backstay is connected to the top of the mast and runs back to the stern of the vessel. A line runs along the backstay which tensions the backstay.
Function: When the Backstay is tensioned the mast bows forward and flattens the middle and top of the sail. This causes a dramatic reduction in draft which depowers the boat and makes it easier to steer and control the boat in a fresh breeze.

Cunningham- The Cunningham is attached just above the tack (forward corner) of the mainsail. It generally runs down to a block attached to the mast just above the deck.
Function: The Cunningham can be used to get more luff (leading edge of sail) tension; used in conjunction with the Outhaul and Backstay is moves the draft forward and completes the depowering of the mainsail.

Halyard- The Halyard is attached to the head (top) of the sail and is used to raise sails to the top of the mast.
Function: The Halyard affects luff tension and draft position. A  loose halyard will create a sail with more draft which is great for a light breeze. As the breeze builds a tighter halyard will give you more luff tension and help give a flatter sail shape (when used in conjunction with the “OBC”s it helps alleviate weather helm).

Sheets- Specifically the Mainsheet is attached to the boom and changes the angle the sail has to the wind (angle of attack).
Function: By changing the angle of attack the speed of the boat can be affected. When the sheets are properly trimmed, the boat is at its greatest efficiency. If we over trim or ease the sails the efficiency will rapidly decrease. Easing the sails upwind, will cause the sails to luff and slow the boat down. Over trimming the sails downwind will stall flow and cause the boat to slow down.

Traveler- The traveler is generally located towards the stern in the cockpit relatively close to the driver position. The mainsheet block is connected to the travel car which travels from one side of the boat to the other.
Function: The Traveler changes the sheeting angle of the Mainsheet. The Traveler is primarily used when going upwind. It is used to bring the boom to center-line on a close haul. It can also be used to depower the boat in a heavy breeze. When feeling over powered the traveler can be “dropped” to the leeward side of the boat to create a luff bubble on the leading edge of the mainsail and effectively reduce its sail area by as much as 25%.

Boom-Vang- The Boom-Vang is connected the boom and runs down to the base of the mast.
Function- The Boom-Vang is primarily used downwind to control leech (trailing edge of sail) tension. It also prevents to boom from rising up into air. If it’s windy and turning downwind is difficult, easing the Boom-Vang before heading down will make it much easier. Just remember to put a little tension back on the Boom-Vang once you’ve turned down to the desired course.

When it’s windy and controlling the boat is becoming difficult just remember your OBC’s: Outhaul, Backstay, Cunningham. J World Annapolis Head Coach, Dave Manhiemmer, uses the simple phrase: “The windier it blows the tighter it goes” to help you remember what to do with your OBC’s when it gets breezy.