must know Nautical Terms

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There are many, many nautical terms that a skilled sailor needs to know. However, if you are completely new to the field, it will most likely be quite difficult for you to learn hundreds of nautical terms.

To give you a little helping hand, we’ve decided to compile a list of 75 must-know nautical terms. This list is by no means comprehensive, but it should be enough for people who know very little or know nothing about the topic.

75 Must-Know Nautical Terms



1. Abandon ship

This is the order to leave the ship immediately. The order must be issued verbally by a delegated person in command. Usually, abandoning a ship is the last resort after all other preventative actions have been exhausted or become impossible and when the loss of the ship is imminent. This command is usually followed by the man the lifeboats order.

2. Amidships

The amidships is the middle section of a boat.

3. Adrift

Adrift means unattached in any way to the shore or seabed. In a broader definition, an adrift ship is one which is not anchored and is not under control. Aside from that, this term is used to refer to any gear that is not properly fastened down or stored.

4. Anchor

An anchor is a method of temporarily “parking” a boat for maintenance or maybe for a lunchtime. It basically is a line or chain with a heavy hook on the end which grips the sea floor to keep the boat in place. Anchors are usually used out in the sea when no port structures are available for parking.

5. Apparent wind

Apparent wind is the direction of the true wind combined with the headwind created by a boat’s motion forward. In other words, it is the wind experienced by a moving boat.

6. Ashore

Ashore is usually used in 3 meanings:

  • On the shore or land.
  • In the direction of the shore.
  • Coming in contact with shore.


7. Baggywrinkle

The baggywrinkle is a soft cover for cables designed to reduce sail chafing.

8. Bar

The bar is a large mass of earth or sand that has been formed by the surge of the sea. Bars are most often found at the entrances of havens and large rivers. Their importance lies in their difficulty to navigate around.

9. Bareboat

To bareboat means to sail a boat on your own. Essentially, bareboating is to sailing as free falling is to skydiving. Bareboating usually implies hiring a vessel, with the vessel’s owner providing no crew or provisions.

10. Beam

The word “beam” is used to refer to the width of a boat at its widest point. Alternatively, it is used to refer to a point at the midpoint of a boat’s length alongside it.

11. Berth

The word berth is used in three meanings:

  • A location in a harbor used to moor ships.
  • A bed or sleeping spot on a ship.
  • The safety margin that needs to be kept between two ships or a ship and an obstruction.

12. Boom

The boom is the metal pole that horizontally sticks out of the mast and is attached to the bottom of the jib (a sail type). By adjusting the direction the boom is facing, it is possible to use the power of the wind in order to propel a boat forward or backward.

13. Bow

The bow is the front of a boat. Anything near the front of a ship is forward. In addition, terms starboard bow and port bow are used to refer to the right and left sides of the bow respectively.

14. Bridle

The bridle is a system that evenly shares the strain on an anchor across two points. The use of this system allows for shock absorption, noise reduction in the anchor chain, as well as reduction of wear in the boat.

15. Buoy

A buoy is a floating object of a specific shape and color that is anchored at some position in the water to serve as an aid in navigation.


16. Cabins

The cabins are the bedrooms on a boat.

17. Catamaran

A catamaran is a type of a boat with two hulls.

18. Chart

A chart is a map that sailors check their position and plan their voyages with.

19. Crow’s nest

The crow’s nest is a lookout placed high up on the mainmast. Crow’s nests are placed as high as possible in order to provide the observer with a good view of the surroundings.


20. Dinghy

A dinghy is a small boat that is designed for quick trips between a ship and the shore.

Aside from that, dinghy is used to refer to small racing yachts or recreational sailing boats. These are often used for beginner training since they are easier to control than large ships.

21. Draft

The draft of a ship is the vertical distance between its keel and the waterline. The draft determines the minimum depth of water a boat can navigate safely. Aside from that, the draft can be used to calculate the weight of the cargo on the board.

22. Dunsel

A dunsel basically is a part of a ship that is useless.


23. Ease

In a nautical context, to ease means let the sails out.


24. Fender

A fender is a rubber bumper hung off the side of a boat in order to protect its hull from impacts and damage. Often, old car tires are used as fenders.

25. Flank speed

The flank speed refers to the true maximum speed of a ship. This term contrasts with the term full speed, which isn’t the maximum speed of a vessel, even though it implies that it is.

What percentage of the flank speed the full speed actually is may vary across ship types. In some ships, the full speed may be just a tad slower than the flank speed. Conversely, in the US nuclear submarine propulsion, full speed usually implies just 50% reactor power.

26. Forepeak

The forepeak is the forward section of a boat’s hull that may be used as a sleeping or storage space, depending on the boat’s design.

27. Flotilla

Flotilla is a military term that refers to a formation of small warships. A flotilla may be part of a larger warship formation. Flotillas are usually composed of 3-20 same-class warships.


28. Galley

A galley is a boat’s kitchen. In addition, this term is used to refer to an ancient oar-propelled ship type used between 700s BC and 1800s AD.

29. Genoa

A genoa is a larger kind of the jib sail that is used to increase the speed of a boat in light to moderate winds. Genoas are commonly used in boat racing events. However, genoas are usually more difficult to handle because they can become tangled with the mast of a boat.

Generally, the term genoa is used to refer to any sail that is larger than a ship’s foretriangle. The foretriangle is the triangular area between the mast, the deck, and the line holding the sail. Sometimes, genoa and jib are used interchangeably.

30. Gybe

A gybe (in the US referred to as jibe) is a downwind (in the same direction as the wind) maneuver in which the ship turns its stern through the wind in order to change the direction from which the wind is blowing. This maneuver is performed alternately by turning the ship from side to side in a zigzag manner.


31. Halyard

Halyards are the lines or ropes that are used to raise sails, ladders, flags, or whatnot. Originally, this term was used to refer to the ropes that hoisted a sail attached to a spar.

32. Heads

Heads is often used by sailors to refer to the toilet.

33. Hold

In its classical meaning, the hold is the inside of a boat’s hull, especially when considered as storage space. In more modern merchant ships, this term was used to refer to the area between the decks and the underside of the weather deck.

34. Heeling

Most frequently, heeling is used to refer to the lean of a sailboat caused by wind. This term is also used in a broader sense to refer to leaning regardless of what causes it (waves or whatnot).

35. Helm

The helm basically is the steering wheel of a ship. This term is also sometimes used to refer to the helmsman who is behind the wheel. On smaller ships, the helm can be a tiller, which essentially is a long wooden stick attached to the steering mechanism of the boat.

36. Hull

The hull is the part of the boat that floats in the water, including the boat’s bottom and sides.


37. In irons

The phrase in irons is used when the bow of the boat is pointing directly into the wind and when the boat is difficult to maneuver. The term in stays is an often used alternative to in irons.

38. Iron Mike

Iron Mike is a slang term used to refer to nautical auto-pilot systems.

39. Itinerary

An itinerary basically is the plan of destinations intended to be visited by a boat. Travel itineraries usually include a schedule of intended destinations, as well as activities for travelers.


40. Jacklines

Jacklines, alternatively referred to as Jack Stays, are lines that run from the bow to the stern on either side of a ship. The ship’s crew connects their safety harnesses to the jacklines for safety.

41. Jib

After the mainsail, the jib is the most common sail seen on boats. It is always found in the front end of the ship. Unlike the mainsail, it doesn’t have a boom. While the contribution of a jib into a boat’s speed is insignificant compared to that of the mainsail, it plays a crucial role in reducing turbulence on the mainsail, thus increasing the boat’s overall stability.


42. Keel

The keel is the structural basis of a boat, running along its hull’s center. It is a long & heavy fin which, sticking down into the water, ensures stability. The keel is the reason why modern sailboats are virtually impossible to capsize.

43. Knot

In a nautical context, knot is used to refer not only to the loop made to secure lines or ropes. The knot is a speed unit equal to one nautical mile per hour.


44. Lazyjack

The lazyjack is a system of lines that connects a boat’s mast to its boom. This system is intended to smoothen the retraction of the sails.

45. Leeward

The leeward is the side of the boat furthest from where the wind is blowing. When the boat is heeling, the leeward is always the low side of the boat.

46. Line

The term lines is used as an alternative to the term ropes. Line is considered the correct term for the majority of ropes or cords on a vessel. Lines always have a more specific name that indicates their use.

47. LOA

Standing for length overall, LOA is the maximum length of a boat’s hull, including the parts that extend beyond the bow and stern. In sailing vessels, the LOA may exclude fittings added to the hull.

48. LWL

Standing for load waterline length, LWL is the length of a boat’s part that is in contact with the water. The LWL is mostly shorter than the LOA since the upper sections of boats’ stern and bow are often protruded.

As a ship’s cargo gets heavier, it will sit lower in the water, with the LWL possibly decreasing. When registering ships, the LWL is usually indicated in a default load condition.


49. Mainsail

The mainsail, as the name suggests, is the main sail of a boat. Being the largest sail on a ship, it catches most of the wind and generates most of the boat’s speed.

50. Mast

The mast is the tall metal pole that goes from the bottom of a boat up into the sky. The mast is designed to provide support for a ship’s sails. If a mast is a wooden multi-part one, the term is used to refer to its lowest portion.

51. Med mooring

Med mooring refers to reversing a boat into a small gap and parking it with its stern facing the quay.

52. Monohull

A monohull, as the name implies, is a boat that has only one hull.

53. Mooring

Mooring is “parking” a ship by attaching it to a permanent structure in a port. This is in contrast with anchoring which is performed when there are no permanent structures nearby for parking.


54. Nautical mile

A nautical mile is a nautical measure of distance equal to 1,852 meters (around 1.1508 miles).


55. Point of sail

The point of sail is the direction of the boat relative to the wind. There are 8 points of sail used in sailing:

  • The no-go zone, which is in the direction where the wind is blowing from (1).
  • Close-hauled, when the wind is on the port or starboard bow (2 & 3).
  • Beam reach, when the wind is on either the port or starboard beam (4 & 5).
  • Broad reach, when the wind is either on the port or starboard quarter (6 & 7).
  • Dead run, when the wind is blowing from behind the ship (8).

56. Port

Port is used to refer to the left-hand side of the bow when facing the bow. Onboard, you may use this term as an alternative to left, and vice versa. All in all, alternative terms for left and right are used in sailing since their more common counterparts can be confusing aboard a ship.

Aside from that, a port is a facility where ships dock to discharge or load cargo and passengers.

57. Prow

The prow is the part of the bow (a ship’s front) above the waterline. Sometimes, terms prow and bow are used interchangeably. Prow may be also used as a poetical alternative to bow.


58. Quay

A quay (also referred to as a wharf or staith) is a metal or stone platform in a harbor or directly in the bank of a water body used by ships for mooring. While the term quay is generally synonymous to wharf, the former is more often used in the UK and the Republic of Ireland, while the latter is more common in the United States.


59. Reefing

Reefing refers to reducing the sail area (i.e. lowering the sails) in order to catch less wind and slow down a boat. This is done to make the ship easier to control. Reefing is often used in choppy conditions or in higher winds.

60. Rip rap

A rip rap is a man-made pile of rubble and rocks used to form a breakwater. Rip raps often surround off-shore lighthouses, vulnerable harbors, as well as other seaside structures that need to be kept away from the raging sea.

61. Rudder

A rudder is a flat piece of fiberglass, metal, or wood that is attached to the bottom of the boat. It is used to steer the ship. In larger sailboats, the rudder is controlled via its steering wheel, while in smaller sailboats, it is controlled with a smaller steering mechanism called tiller.


62. Sails

The sails are large fabric pieces hung from the mast and used to propel a ship forward. Sails rely on wind, which, on one hand, is an eco-friendly method of propulsion and on the other makes sailboats very sensitive to weather conditions.

63. Saloon

The saloon is the living area in a boat, usually down below the deck.

64. Skipper

The term skipper is used to refer to the captain of a boat.

65. Starboard

The starboard is the right-hand side of a boat when facing the bow. This makes the term starboard the opposite of port.

66. Stern

The stern is the rear of a boat. Furthermore, anything near the rear of a boat is referred to as being astern or aft.


67. Underway

When a boat is moving – either by wind or motor power – it is said that it is underway.


68. Tacking

Tacking is a maneuver in which a ship, whose course lies into the wind, turns its bow toward the wind in order to change the direction from which the wind blows. Like it was with the gybe, this maneuver is done in a zig-zagging manner, alternating the directions from which the wind blows. Tacking is an efficient method of sailing upwind and is the opposite of jibing.

The word tack may be used as either a verb or a noun. As a verb, it is used to refer to performing the tacking maneuver. As a noun, the tack is a boat’s course relative to the wind. For example, if the wind is blowing from the right side of the ship, it is on a starboard tack. Likewise, if the wind is blowing from the left, the ship is on a port tack.

69. Topside

When you are moving from a boat’s lower deck to an upper deck, you are going topside.

70. Trim

The term trim refers to the adjustments made to the sail which are aimed at maximizing its efficiency. Aside from that, this term refers to the position of the hull in relation to the waterline.

71. True wind direction

The true wind direction is the direction from which the wind is actually blowing.


72. Waterline

The waterline is the line on a ship’s hull where the hull meets the sea.

73. Winch

A winch is a mechanical device with a rotating handle that is used to wind lines or ropes up and out. Winches are usually used to control anchors, but they may be used in many other nautical applications as well.

74. Windward

The opposite of leeward, the windward is the side of the boat closest to where the wind is blowing from. When the boat is heeling, its windward is always the high side.


75. Yacht

Generally speaking, a yacht is any vessel that is used for pleasure, racing, or cruising. Yachts differ significantly by their design, with some being sailed and others propelled by motors.