Study Guide Definitions and Terms
Abaft – Abaft indicates that something is behind something else. If an object is located behind the port beam, then one says that it is “abaft” the port beam.
Abeam – At right angles to the centerline of the boat but not on board the boat. Abeam means a perpendicular direction that is straight out from the middle of the vessel on either side. For example, a direction straight out from the left-hand side at the middle of a vessel is referred to as “on the port beam”.
Abeam to port – When one says that an object in the water is abeam to port, one means that the object is straight out from the port beam.
Abeam to starboard – When one says that an object in the water is abeam to starboard, one means that the object is straight out from the starboard beam.
Aboard – On or within the boat
Above deck – On the deck of a boat (not above the deck - see “Aloft”)
Aft – Like the term abaft, the term aft also indicates a direction toward the stern. If one is moving to the stern of a vessel, then one is going “aft”.
Aground – Touching or stuck on the bottom
Ahead – Ahead refers to a direction directly in front of a vessel.
Aids to Navigation – Aids to navigation are systems, structures, or devices that are external to a vessel and that aid the operator in navigation, indicate safe routes, and warn of obstacles or dangers. Aids to navigation can include such things as buoys, day beacons, and lighthouses. “Aids to navigation” should not be confused with “navigational aids”.
Alee – Away from the direction of the wind (opposite of windward)
Aloft – Above the deck of a boat
Amidships – In or at the point midway between the bow and the stern
Anchor – An anchor is a heavy object that is attached to a rope or chain and used to moor a vessel to the bottom. Typically, an anchor has a metal shank with a ring at one end for the rope and a pair of curved and/or barbed flukes at the other
Anchor rode – A vessel is attached to its anchor by the rode, which is made of chain, cable, rope, or a combination of these.
Astern – In back of a boat, opposite of “ahead”. Astern is a direction behind a vessel. The term “dead astern” means directly behind the vessel.
Athwartships – At right angles to the centerline of the boat.
Aweigh – Refers to the position of an anchor when it is raised clear of the bottom.
Beam – Technically, the beam is the width of a vessel at its widest point. The widest point of a hull is traditionally at the midpoint between the bow and the stern. Thus, “beam” came to be the nautical term for the part of the vessel midway between a vessel's bow and stern.
Bearing – The direction to an object, expressed two ways:
- As a true bearing as shown on a chart; or
- As bearing relative to the heading of your boat.
Below – Beneath the deck
Bilge – The bottom part of the inside of a ship or boat.
Bitter End – The outboard end of a line attached to a boat. Or the inboard end of a anchor rode.
Bow – The front end of a boat.
Bow line – A line attached to the bow of a boat
Bowline – A knot used to form a temporary loop in the end of a line
Bridge – The control station from which a vessel is steered and its speed is controlled.
Bulkhead – A vertical partition separating two compartments in a vessel
Buoy – An anchored float used for marking a position on the water or a hazard or a shoal and for mooring.
Capsize – To turn upside down.
Cast off – To let go.
Catamaran – A boat with two hulls arranged side by side.
Chart (nautical) – A nautical chart is map (a graphic representation) of a marine areas and adjacent shorelines and land areas. Depending on the scale of the chart, it may show depths of water and heights of land (topographic map), natural features of the bottom, details of the shoreline, navigational hazards, locations of natural and human-made aids to navigation, information on tides and currents, local details of the Earth's magnetic field, and human-made structures such as harbours, buildings, and bridges.
Chine – A chine is the line where the bottom of a boat curves up and turns into the side of the boat (i.e.: it is intersection between the bottom of a boat and sides of the boat.
Chock – A fitting through which anchor or mooring lines are led. It is usually U-shaped to reduce chafe on the line.
Cleat – A fitting to which lines are tied on (made fast). The classic cleat to which lines are made fast is approximately anvil-shaped.
Coaming – A vertical piece around the edge of a cockpit, hatch, etc. to prevent water on deck from running below.
Coil – To lay a line down in circular turns.
Cockpit – An opening in the deck from which the boat is handled.
Commercial vessel – A commercial vessel is any vessel that is used to earn revenue. Commercial vessels include water taxis, tour boats, freighters, tankers, ferries, fishing boats, tugboats, and excursion boats.
Course – The direction in which a boat is being steered.
Current – The horizontal movement of water.
Dead ahead – Directly ahead of the vessel.
Dead astern – Directly aft of the vessel.
Deck – A permanent covering over a compartment, hull or any part thereof.
Dinghy – A small open boat that is often used as a tender for a larger craft.
Displacement – The volume of water which is displaced by a floating vessel and which is equal in weight a the vessel's weight.
Displacement vessel – A type of vessel with a hull that plows through the water, displacing a weight of water equal to its own weight, and does not plane but instead continues to plow, even at the craft's maximum speed.
Dock – A pier or a wharf for mooring boats.
Downwind – The direction in which wind is blowing.
Draft – The depth of water a boat draws. The draft is the minimum depth of water that a vessel requires to float freely. It is approximated as the distance between the water surface and the lowest point of the vessel. On a boat equipped with an outboard motor, the draft is usually the distance from the surface of the water to the bottom of the lowest point on the engine (i.e.: the bottom of the skeg). You need to know the draft of your boat so that you may refer to marine charts to determine which waters are deep enough for your boat.
Ebb – A receding current
Fathom – A unit of measure that is equal to six (6) feet.
Fender – A cushion, placed between boats, or between a boat and a pier, to prevent damage. Fenders are various devices (usually hollow cylinders made of plastic) that are hung from the side a vessel to prevent surface damage to the vessel when it rubs against a dock or against another vessel.
Flare – A type of distress signal.
Flood – A incoming current.
Fluke – The palm of an anchor.
Following sea – An overtaking sea that comes from astern.
Fore and aft – In a line parallel to the keel.
Forepeak – A compartment in the bow of a small boat.
Forward – Toward the front of a boat.
Fouled – When a piece of equipment is jammed, entangled, or dirty.
Freeboard – Freeboard is the minimum vertical distance from the surface of the water to a boat's gunwale. A vessel with a high freeboard (i.e.: a deck that is high above the water) is difficult to re-board from the water without the aid of re-boarding equipment.
Galley – The kitchen area of a boat.
Gangway – The area of a ship's side where people board and disembark.
Gear – A general term for ropes, blocks, tackle and other equipment.
Give-Way Vessel – The vessel that according to the Rules of the Road must yield in meeting, crossing, or overtaking situations.
Ground tackle – A collective term for the anchor and its associated gear.
Gunwale – The gunwale (pronounced “gunnel”) is the top edge of a boat's sides.
Hard chine – An abrupt intersection between the bottom and the side on a boat hull.
Head – A marine toilet.
Heading – A direction or bearing. The direction in which a vessel's bow points at any given time.
Headway – The forward motion of a boat. Opposite of sternway.
Hitch – A knot used to secure a rope to another object or to another rope, or to form a loop or a noose in a rope.
Hold – A compartment below deck in a large vessel, used solely for carrying cargo.
HSN – All pleasure craft (with or without a motor) used in Canada must bear a hull serial number (HSN). No character of the HSN is to be less than 3.2 cm (1 ¼ in.) in height or width. The HSN is 12 digits in length (beginning with the manufacturer's code) and must be permanently marked on the exterior upper starboard corner of the boat's transom.
Hull – The hull is the main body of a boat, from the deck down. It should be thought of as an empty shell; it does not include equipment or fittings (pumps, motors, pumps, cabins, bilges, etc.)
Inboard – More toward the center (inside) of a vessel.
Inboard motor – A motor fitted inside a boat.
Jacob's ladder – A rope ladder, lowered from the deck, as when pilots or passengers come aboard.
Jetty – A structure, usually masonry, projecting out from the shore; a jetty may protect a harbor entrance.
Keel – The centerline of a boat running fore and aft; the backbone of a vessel.
Knot – A measure of speed equal to one nautical mile (6,076 feet) per hour.
Knot – A fastening made by interweaving rope to form a stopper, to enclose or bind an object, to form a loop or a noose, to tie a small rope to an object, or to tie the ends of two small ropes together.
Lee – The side of a vessel or land mass that is sheltered from the wind.
Leeward – The direction away from the wind. Opposite of windward. Leeward means downwind; the direction in which the wind is blowing. The leeward side of an island is the side that is sheltered from the wind.
Leeway – The sideways movement of the boat caused by either wind or current.
Length overall – The length overall of a vessel is the distance from the foremost point on the hull (above or below the waterline) to the aft-most point on the hull (above or below the waterline). When a regulation is applied to a vessel based on its length, the regulation is referring to the “length overall” as defined here.
Life jacket – A life jacket is a flotation device that is designed to keep a person face-up in the water, even when that person is unconscious.
Line – Rope and cordage used aboard a vessel.
Log – A record of courses or operation. Also, a device to measure speed.
Lubber's line – A mark or permanent line on a compass indicating the direction forward parallel to the keel when properly installed.
Midship – Also referred to as amidships, midship is approximately in the location equally distant between the bow and stern.
Mooring – An arrangement for securing a boat to a mooring buoy or a pier.
Nautical mile – One minute of latitude; approximately 6,076 feet - about 1/8 longer than the statute mile of 5280 feet.
Navigational aids – Navigational aids are shipboard tools (such as a radar system or a sonar system, GPS, compass, sextant, or marine charts) that aid in determining one's position and setting course.
On the port stern – Off the port stern (sometimes termed “off the port quarter”) means
On the starboard stern – Off the starboard stern (sometimes termed “off the starboard quarter”) means
Operator – The operator of a vessel is the person in charge of the craft. This is an important distinction to make. Thus, when you borrow a boat and take it out on the water, you (not the person you borrowed it from) are the operator. Under Canadian regulations, the operator of a pleasure craft is responsible for its condition, how it is operated, and the safety of all on board.
Outboard – Toward or beyond the boat's sides.
Outboard motor – A detachable engine mounted on a boat's stern.
Overboard – Over the side or out of the boat.
Personal water craft – Seadoos and jet skis are referred to as personal water craft (PWCs) and are considered to be power-driven (motorized) pleasure craft.
Pier – A loading platform usually extending into the water at an angle perpendicular to the shore extending at an angle from the shore.
Planing – A boat is said to be planing when it is essentially moving over the top of the water rather than through the water.
Planing vessel – A boat with a hull that is designed to plane at high speed.
Pleasure craft – According to Transport Canada, a pleasure craft is any type of watercraft used exclusively for pleasure and not for carrying passengers or goods for hire.
Pleasure Craft Operator Card – The Pleasure Craft Operator Card (PCOC) is not a government-issued license; it is a certificate issued by a privately owned accredited course provider (ACP) that confirms that the holder passed a Transport Canada Boating Safety Test. Anyone operating a motorized pleasure craft in Canada must carry proof of competency.
Port side – The port side is the side of the boat that is on your left side when you are standing in the boat and facing forward.
Power-driven vessel – A power-driven vessel is one that is propelled by any type of engine or machinery (including steam engines and electric trolling motors). All operators of power-driven pleasure craft must obtain a PCOC and carry it on board.
Proof of competency – According to the Competency of Operators of Pleasure Craft Regulations(COPCRs), regardless of age or nationality all persons must carry proof of competency whenever operating any type of motorized pleasure craft on any Canadian waters (other than the waters of the Northwest Territories and Nunavut). Original proof of competency (not a photocopy) must be carried on board when operating a motorized pleasure craft anywhere in Canada (proof of competency is not required for vessels without motors). Proof of competency can take any of four forms:
- Pleasure Craft Operator Card (PCOC);
- Proof that you successfully completed a boating safety course in Canada before April 1, 1999 (i.e.: a boating safety certificate issued before 1999);
- A completed boat rental safety checklist (temporary proof); or
- Alternative acceptable proof of competency.
The most common proof of competency is the Pleasure Craft Operator Card (PCOC).
Quarter – The sides of a boat aft of amidships.
Quartering sea – A sea coming on a boat's quarter.
Rode – A vessel is attached to its anchor by the rode, which is made of chain, cable, rope, or a combination of these.
Rope – Rope is the term for cordage as it is purchased at a store. When put to use on a boat, rope is referred to as line.
Rudder – A vertically-oriented plate or board that is used for steering a boat.
Running lights – Lights that are required to be shown on boat when it is underway between sunrise and sunset.
Sail-driven vessel – Any vessel under sail provided that propelling machinery, if fitted, is not being used. Thus, even if a sailboat has its sails raised, it is considered to be a power-driven vessel whenever it is being propelled by a motor and, thus, it must obey the Collision Regulations for power-driven vessels. Also, the operator must carry proof of competency if the sailboat is fitted with a motor. The PCOC must be carried even when under sail without the motor in operation.
Seaworthy – A vessel is considered seaworthy if:
- The hull is undamaged and the boat is appropriate for the type of sea condition in which it is being used;
- The engine size does not exceed the allowable maximum for that vessel;
- The vessel is not overloaded: and
- All equipment is in good working order.
Knowingly operating a vessel that is not seaworthy is a violation of the Criminal Code. Thus, if one operates a boat that is overloaded or that is fitted with an engine that is too large, then one is guilty of a criminal offence.
Scope – Scope is the ratio of the length of the anchor rode in use to the vertical distance from the bow of the boat to the bottom. Anchoring with sufficient scope (i.e.: sufficient anchor rode) brings the direction of strain on the anchor line close to parallel with the bottom. In good weather and calm water, the scope ratio should range between 6 to 1 and 7 to 1. In poor weather or in strong currents, the rode ratio must be increased (i.e.: more anchor line must let out.
Sea room – A safe distance from the shore or other hazards.
Ship – A larger vessel usually thought of as being used for ocean travel.
Sounding – A measurement of the depth of water.
Starboard side – The side of the boat that is on your right side when you are standing in the boat and facing forward.
Squall – A sudden, violent wind often accompanied by rain.
Stand-on vessel – That vessel which has right-of-way during a meeting, crossing, or overtaking situation.
Starboard-side – The right side of a boat when looking forward.
Stem – The forward most part of the bow.
Stern – The aft end (back-end) of a boat.
Tender – A tender is a boat used to service or support other boats or ships, generally by transporting people or supplies to the ship and vice versa.
Tide – The periodic rise and fall of water level in the oceans.
Tiller – A bar or handle for turning a boat's rudder or an outboard motor.
Transom – The stern cross-section of a square-stern boat.
Trim – The fore and aft balance of a boat.
Underway – Underway means that a vessel is not at anchor, tied to a dock, or pulled up on shore; i.e. a vessel is considered to be underway if it is afloat and free to move. If a vessel is not moored, not at anchor and not aground, then it is underway.
Upwind – A direction into the wind, toward where the wind is coming from.
Vessel – A vessel is any type of waterborne craft (other than a seaplane) that is capable of being used as a means of transport.
V-bottom - A hull with a cross-section in the shape of a “V”.
Wake – The wake of a vessel is the disturbed water and waves around and behind a vessel that are set in motion by its passage through the water. Thus, a vessel must be moving through the water in order to create a wake. Similarly, an airplane must be moving through the air to create a wake.
Wash – Wash is the loose or broken water left behind by a boat as it moves through water and includes the churned water thrown aft by the propeller (i.e. propeller wash). Just as an airplane can create prop wash when sitting on the ground, a vessel does not have to be moving through the water in order to create wash.
Waterline (design) – The design waterline of any vessel is the line corresponding to the surface of the water when the vessel is afloat, carrying a normal load, and on an even keel. The design waterline is often indicated with a horizontal line painted on the exterior of a vessel's hull.
Way – The movement of a vessel through the water such as headway, sternway or leeway.
Windward – Windward is a direction into the wind. It is the direction from which the wind is blowing. The windward side of an island is the side onto which the wind blows.
Windward side of a sail-driven vessel – The windward side of a sail-driven vessel is the side of the vessel that is opposite to the side on which the mainsail is being carried.
Yaw – To swing or steer off course