What is a Sailboat Sheet?

What is a Sailboat Sheet?

A sailboat sheet is a rope or line connected to the clew of a sail (in the bottom corner) or the boom. From the boom or clew, the sheet often runs down to a series of blocks and winches on the deck. Sailors control the sheets from these winches and blocks.

Mainsheet

The mainsheet controls the lateral movement of the boom and the mainsail. This is often the most important sheet onboard a sailboat. It's also the closest, as the boom hangs over the cockpit of the sailboat.

Jib sheet

The jib sheet controls the front triangular sail. It runs across the length of the deck and often includes two separate lines. When changing direction, sailors release the cleat and winch, securing one side of the jib sheet, and engage the other, allowing the jib to swing to the other side.

Basic Sailboat Sheet Rigging

Small sailing dinghies use the simplest forms of sheet rigging. In many cases, the sheet of a small sailboat is simply a section of rope hanging from the boom, which the sailor holds on to and pulls in and out.

Other small vessels have a simple block system mounted to a fixed point on the deck, which allows the operator to tether the sheet in place. Small boats often avoid these systems as they're sensitive to minute wind changes.

Block and Tackle

The mainsheet feeds through a complex system of blocks (pulleys), cleats, and winches. These rigging systems allow the boom to swing to either side, which is especially useful when tacking quickly. Here are two common types of mainsheet rigging, otherwise known as 'tackle' systems.

Gun Tackle

Gun tackle is one of the simplest block and tackle systems used on sailboats. It requires only two blocks, which are usually positioned towards the end of the boom on the stern of the vessel.

Gun Tackle only utilizes two sections of rope in the blocks, which provides the lowest level of force reduction. As a result, this block and tackle system is typically found on smaller sailboats where the size of the sail plan requires less effort to manage.

Luff Tackle

Luff tackle is much more common on cruising sailboats, and it's still fairly simple to operate. Luff tackle is easier to pull (requires less force) than gun tackle, as it includes three sections of rope instead of two. Remember, each section of rope reduces the force required to pull in the sheet.

The main disadvantage to luff tackle (and other high-ratio block and tackle systems) is increased sheet length. Longer lines increase the chances of tangling, which can be a nightmare at sea. However, a properly-rigged sailboat and a trained crew can reduce the chances of fouling up the mainsheet.

Mainsheet Travellers

Travelers are extremely useful for trimming the sail. The system allows sailors to adjust the "twist" of the mainsail, which helps control the speed more precisely. The mainsheet block mounts to the sliding traveler and moves side to side.

Mainsheet Bridle vs. Mainsheet Traveller

A bridle is a simple alternative to a traveler, and it comes in many configurations. A standard dinghy-style bridle feeds the mainsheet through two deck-mounted blocks, which allows the operator to center the boom. Other vessels use a single block on a sliding rail, which serves the same purpose.

Travelers are more complex, but they offer superior power and trim control on larger boats. The primary advantage of a traveler is the ability to precisely adjust the twist of the sail, which is especially important in windy and stormy conditions.

Jib sheet

Sailboat jib sheets utilize more than one section of rope or line. Instead of a single line connected to the boom, the jib uses one line on either side of the sail. Jib sheets connect to the jib through a clew located at the bottom corner of the canvas.

The jib sheet works in a similar way to the mainsheet. Tightening one side of the sheet pulls the bottom corner of the jib in that direction and helps control the boat. When one side of the jib sheet is taught, the other side is loosened.

The jib sheet utilizes two separate sections of the rope that run along the port and starboard side of the deck. The advantage of using two lines is that there's no need to unwrap the sheet from the mast when changing direction.

The sheets travel from the clew of the jib to a set of blocks towards the bow of the boat. From there, the lines often run through a set of cam cleats and to their respective winches.

When changing direction to the wind, sailors loosen one section of the jib sheet and release tension from the cleat and the winch. Then, they feed the opposite line into the cam cleat and tighten the winch. This process prepares the jib to switch sides.

Sailboat Sheet Winches

Sailboats utilize winches for the mainsheet and the jib sheet. Winches allow sailors to increase and decrease line tension by winding around a cammed drum. Winches include a removable winding crank or a motor.

The cam inside the winch works like a socket wrench or a bicycle sprocket, allowing sailors to wind against pressure and lock one direction of travel. Sailors can switch the direction of the cam for winding and unwinding.

Manual Winches

Manual winches are common on sailboats of all sizes. These winches are wound manually using a removable crank or 'key,' which fits into the top of the drum. Manual winches are sometimes difficult to wind by hand, especially in windy conditions.

Power Winches

High-end modern sailboats often utilize motorized winches. These electrified systems allow sailors to wind heavier loads. Additionally, electric winches can be controlled from a protected pilothouse. Advanced electric winch systems allow the sail to be trimmed without stepping foot on deck.

Best Line for Sailboat Sheets

Sailboat sheets control the speed of the boat, so it's essential to choose a durable and long-lasting line material. It's also necessary to quickly replace aged and frayed sheet lines, as degraded lines can snap, tangle, and bind up without warning. Here are the best materials for sailboat sheet rigging.

Polyester Sheet Line

Polyester is an affordable and robust material for sailboat sheets. It's extremely common on all kinds of sailboats. Polyester is ideal because it's strong, resists decay, and it doesn't stretch easily. Polyester line is a trusted go-to for typical day-sailing activities.

Polyester has a few disadvantages. For one, it absorbs water readily and breaks more easily than high-strength lines. It's fine for most leisure sailing activities, but better alternatives exist for serious cruising.

Aramid (Kevlar) Sheet Line

Aramid (Kevlar) line is a high-strength alternative to polyester, and it's ideal for marine applications, including sailboat sheets. Kevlar line consists of tightly woven strands of ultra-strong aramid fiber, which is highly resistant to heat, weather, stretching and fraying. Aramid line is trusted onboard serious cruising sailboats all over the world.

Kevlar is stronger than polyester, sheds water better, and stretches less. But strength comes at a cost—kevlar lines aren't as flexible as polyester, and they tend to become brittle when exposed to the sun for too long.

HMPE Sheet Line

HMPE (High Modulus Synthetic Fiber) is a space-age material that solves most of the problems caused by polyester and aramid sheet lines. HMPE is a premium woven fiber material that is (quite literally) one of the strongest synthetic fibers available to sailors. It doesn't stretch, and it's highly resistant to weather and wear.

HMPE is the material of choice for competitive sailboats and blue water vessels. The primary downside of HMPE lines is cost, as this fiber is quite expensive when compared to relatively affordable aramid and dirt-cheap polyester.