Points of sail
Overview
 
Points of sail describes a sailing
Sailing
Sailing is the propulsion of a vehicle and the control of its movement with large foils called sails. By changing the rigging, rudder, and sometimes the keel or centre board, a sailor manages the force of the wind on the sails in order to move the boat relative to its surrounding medium and...

 boat's course in relation to the wind direction.

There is a distinction between the port tack and the starboard tack. If the wind is coming from anywhere on the port side, the boat is on port tack. Likewise if the wind is coming from the starboard side, the boat is on starboard tack. Except when head to wind, a boat will be on either port or starboard tack while on any point of sail.
Encyclopedia
Points of sail describes a sailing
Sailing
Sailing is the propulsion of a vehicle and the control of its movement with large foils called sails. By changing the rigging, rudder, and sometimes the keel or centre board, a sailor manages the force of the wind on the sails in order to move the boat relative to its surrounding medium and...

 boat's course in relation to the wind direction.

There is a distinction between the port tack and the starboard tack. If the wind is coming from anywhere on the port side, the boat is on port tack. Likewise if the wind is coming from the starboard side, the boat is on starboard tack. Except when head to wind, a boat will be on either port or starboard tack while on any point of sail. For purposes of the International Regulations for Preventing Collisions at Sea
International Regulations for Preventing Collisions at Sea
The International Regulations for Preventing Collisions at Sea 1972 are published by the International Maritime Organization , and set out, inter alia, the "rules of the road" or navigation rules to be followed by ships and other vessels at sea in order to prevent collisions between two or more...

 and the Racing Rules of Sailing
Racing Rules of Sailing
The Racing Rules of Sailing govern the conduct of yacht racing, windsurfing, kitesurfing, model boat racing, dinghy racing and virtually any other form of racing around a course with more than one vessel while powered by the wind...

, the wind is assumed to be coming from the side opposite that which the boom
Boom (sailing)
In sailing, a boom is a spar , along the foot of a fore and aft rigged sail, that greatly improves control of the angle and shape of the sail. The primary action of the boom is to keep the foot of the sail flatter when the sail angle is away from the centerline of the boat. The boom also serves...

 is carried.

No-go zone

Sailboat
Sailboat
A sailboat or sailing boat is a boat propelled partly or entirely by sails. The term covers a variety of boats, larger than small vessels such as sailboards and smaller than sailing ships, but distinctions in the size are not strictly defined and what constitutes a sailing ship, sailboat, or a...

s cannot sail
Sailing
Sailing is the propulsion of a vehicle and the control of its movement with large foils called sails. By changing the rigging, rudder, and sometimes the keel or centre board, a sailor manages the force of the wind on the sails in order to move the boat relative to its surrounding medium and...

 directly into the wind, nor on a course
Course (navigation)
In navigation, a vehicle's course is the angle that the intended path of the vehicle makes with a fixed reference object . Typically course is measured in degrees from 0° clockwise to 360° in compass convention . Course is customarily expressed in three digits, using preliminary zeros if needed,...

 that is too close to the direction
Wind direction
Wind direction is reported by the direction from which it originates. For example, a northerly wind blows from the north to the south. Wind direction is usually reported in cardinal directions or in azimuth degrees...

 from which the wind is blowing. The range of directions into which a boat cannot sail is called the no-go zone. Its width depends on the design of the boat, its rig
Rigging
Rigging is the apparatus through which the force of the wind is used to propel sailboats and sailing ships forward. This includes masts, yards, sails, and cordage.-Terms and classifications:...

, and its sail
Sail
A sail is any type of surface intended to move a vessel, vehicle or rotor by being placed in a wind—in essence a propulsion wing. Sails are used in sailing.-History of sails:...

s, as well as on the wind strength
Beaufort scale
The Beaufort Scale is an empirical measure that relates wind speed to observed conditions at sea or on land. Its full name is the Beaufort Wind Force Scale.-History:...

 and the sea state
Sea state
In oceanography, a sea state is the general condition of the free surface on a large body of water—with respect to wind waves and swell—at a certain location and moment. A sea state is characterized by statistics, including the wave height, period, and power spectrum. The sea state varies with...

. Depending on the boat and the conditions, the no-go zone may be from 30 to 50 degrees either side of the wind, a 60 to 100 degree area centered on the wind direction.

When attempting to sail into the no-go zone, the boat's sails do not produce enough drive to maintain way or forward momentum through the water. Therefore the boat will eventually coast to a stop, with the rudder
Rudder
A rudder is a device used to steer a ship, boat, submarine, hovercraft, aircraft or other conveyance that moves through a medium . On an aircraft the rudder is used primarily to counter adverse yaw and p-factor and is not the primary control used to turn the airplane...

 becoming less and less effective at controlling the direction of travel.

A sailboat's ability to sail close to the wind is referred to as its "pointing" ability. A yacht designed primarily for racing
Yacht racing
Yacht racing is the sport of competitive yachting.While sailing groups organize the most active and popular competitive yachting, other boating events are also held world-wide: speed motorboat racing; competitive canoeing, kayaking, and rowing; model yachting; and navigational contests Yacht racing...

 can typically point from 30 or at least 40 degrees from the wind direction, whereas one designed for cruising
Cruising (maritime)
Cruising by boat is a lifestyle that involves living for extended time on a boat while traveling from place to place for pleasure. Cruising generally refers to trips of a few days or more, and can extend to round-the-world voyages.- History :...

 may only be able to point 40 to 50 degrees from the wind direction. Working boats may not be able to point this well and square rig
Square rig
Square rig is a generic type of sail and rigging arrangement in which the primary driving sails are carried on horizontal spars which are perpendicular, or square, to the keel of the vessel and to the masts. These spars are called yards and their tips, beyond the last stay, are called the yardarms...

ged vessels certainly cannot. The size of the no-go zone varies, but all sailboats have one.

A boat turns through the no-go zone as it performs a tack
Tack (sailing)
Tack is a term used in sailing that has different meanings in different contexts, variously a part of a sail, and an alignment with the wind. When using the latter sense, the maneuver of turning between starboard and port tack is either tacking or jibing....

. Since the boat is passing through the no-go zone, it must maintain momentum until it has turned all the way through this area. If a boat loses way and steerage before it exits the no-go zone, it is said to be "in irons," and may stop, return to the original tack, or begin to travel slowly backwards.

In irons

If the boat attempts to tack with a slow initial speed, or otherwise loses forward motion while heading into the wind, the boat will coast to a stop and the lack of water flow over the rudder will cause the sailor to lose the ability to steer the boat. Stopped head-to-wind, a sailboat is said to be "in irons". To recover from being in irons, one or more sails can be "backed" by sheeting or pushing them to one side. A sail backed to one side near the bow of the boat will tend to push the bow to the other side, and the boat may "pay off" in that direction so that the sails can be trimmed again and normal sailing resumed. A sail backed further aft may make a boat begin to "sternboard" or make way backwards. If this is possible the rudder can be used to steer the boat out of the no-go zone.

Close hauled

A boat is sailing close hauled (also called beating or working to windward) when its sails are trimmed in tightly and it is sailing as close to the wind as it can without entering the no go zone. This point of sail lets the boat travel diagonally to the wind direction, or "upwind". A boat is considered to be "pinching" or "feathering" if the helmsman tries to sail above an efficient close-hauled course and the sails begin to luff slightly. This can be an effective technique to maintain control of the boat on a windy day by "de-powering", or spilling some wind, but is otherwise inefficient.

Reaching

When the boat is traveling approximately perpendicular to the wind, this is called reaching. A 'close' reach is somewhat toward the wind, and 'broad' reach is a little bit away from the wind (a 'beam' reach is with the wind precisely at a right angle to the boat). For most modern sailboats, reaching is the fastest way to travel. On some boats, the beam reach is the fastest point of sail; on others, a broad reach is faster.

Beam reach

This is a course steered at right angles to the wind on either port or starboard tack. This is a precise point of sail, with sails put out at roughly 45 degrees.

Broad reach

The wind is coming from behind the boat at an angle. This represents a range of wind angles between beam reach and running downwind. The sails are eased out away from the boat, but not as much as on a run or dead run (downwind run).

Running downwind

On this point of sail (also called running before the wind), the wind is coming from directly behind the boat. Running can be dangerous to those on board in the event of an accidental jibe
Jibe
A jibe or gybe is a sailing maneuver where a sailing vessel turns its stern through the wind, such that the wind direction changes from one side of the boat to the other...

.

When running, the mainsail is eased out as far as it will go. The jib will collapse because the mainsail blocks its wind, and must either be lowered and replaced by a spinnaker or set instead on the windward side of the boat. Running with the jib to windward is known as gull wing, goose wing, butterflying or wing and wing. In Scandinavian languages this is known as psalmbooking. A genoa
Genoa (sail)
The genoa or jenny was originally referred to as the 'overlapping jib' or the Genoa jib, being named after the city of Genoa as explained below. It is a type of large jib or staysail used on bermuda rigged craft that overlaps the main sail, sometimes eliminating it. It is used on single-masted...

 gull-wings well, especially if stabilized by a whisker pole, which is similar to, but lighter than a spinnaker pole
Spinnaker pole
A spinnaker pole is a spar used in sailboats to help support and control a variety of headsails, particularly the spinnaker. However, it is also used with other sails, such as genoas and jibs, when sailing downwind with no spinnaker hoisted...

.

Racing sailboats typically set a spinnaker
Spinnaker
A spinnaker is a special type of sail that is designed specifically for sailing off the wind from a reaching course to a downwind, i.e. with the wind 90°–180° off the bow. The spinnaker fills with wind and balloons out in front of the boat when it is deployed, called flying. It is constructed of...

 when sailing any point of sail from beam reach to a run. In 'non-extras' or 'no flying sails' class, where spinnakers are not permitted, poled-out genoas are often used when running downwind. In College and High School style racing, where neither spinnakers or poles are permitted, the jib is winged opposite the main and the boat heeled to windward to help maintain sail shape without a pole. Cruising yachtsmen, when running downwind, will often set either a poled-out genoa or a pole-less cruising 'chute (or gennaker
Gennaker
A gennaker is a sail that was developed around 1990. Used when sailing downwind, it is a cross between a genoa and a spinnaker. It is asymmetric like a genoa, but the gennaker is not attached to the forestay like a jib or genoa. The gennaker is rigged like a spinnaker but the tack is fastened to...

). When running downwind for protracted periods, for example when ocean-crossing in steady trade winds, cruisers sometimes set twin poled-out jibs without a mainsail. All of these options are more stable and require less trimming effort than a spinnaker.

Steering can be difficult when running because there is less pressure on the tiller to provide feedback to the helmsman, and the boat is less stable, meaning the boat may more easily go off course than on other points of sail. This tendency to turn off course when running can be dangerous. If a boat turns to leeward too far, or sails "by the lee", the boat can jibe accidentally if the lee side of the sail catches the wind, causing the boom to swing across the boat quickly. A preventer
Preventer
A preventer, or jibe-guard, is a mechanical device on a sailing vessel which limits the boom's ability to swing unexpectedly across the boat due to an unplanned accidental jibe....

 can be used on yachts to help avoid this. Some boats, particularly smaller racing dinghies like the Laser, sail "by the lee" very well, but most sailboats should be careful to avoid this, and a vigilant helmsman is important.

Also when sailing on a dead downwind run an inexperienced or inattentive sailor can easily misjudge the real strength of the wind since the boat speed subtracts directly from the true wind speed
Wind speed
Wind speed, or wind velocity, is a fundamental atmospheric rate.Wind speed affects weather forecasting, aircraft and maritime operations, construction projects, growth and metabolism rate of many plant species, and countless other implications....

 and this makes the apparent wind
Apparent wind
Apparent wind is the wind experienced by a moving object.-Definition of apparent wind:The Apparent wind is the wind experienced by an observer in motion and is the relative velocity of the wind in relation to the observer....

 less. In addition the sea conditions also falsely seem milder on this point of sail as developing white caps are shielded from view by the back of the waves and are less apparent. When changing course in a brisk wind from a run to a reach or a beat, a sailboat that seemed under control can instantly become over-canvassed and in danger of a sudden broach
Broach (sailing)
A sailboat broaches when its heading suddenly changes towards the wind due to wind/sail interactions for which the rudder cannot compensate. This causes the boat to roll dangerously and if not controlled may lead to a capsize...

.
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