Aircraft carrier A large military ship with a main deck that serves as a runway from which aircraft take off and land. Aircraft are kept in hangars below deck.

Ballast tank A compartment low in a ship’s hull that can be filled with water, or emptied. A ship may fill its ballast tank to make it sit lower in the water and so stabilize it. In a submarine, ballast tanks are filled with water to make it dive or emptied to make it surface.

Bow The front part of a ship, also known as fore. In many ships it is pointed.

Bridge A room high up on a ship, from where the crew steer and control the ship.

Cargo ship A large ship, also known as a freighter, that transports cargo.

Catamaran A boat with two hulls, connected by one or more decks. Some catamarans are fitted with sails and used for racing. Larger models have diesel engines and are used as high-speed ferries.

Container ship A ship that carries cargo in large metal boxes called containers. These are loaded and unloaded using cranes, or rolled on and off in port.

Cruise ship A large passenger ship designed for holiday cruising.

Deck The horizontal floor of a ship.

Dredger A ship that digs out sediment from the seabed in order to keep waterways deep enough for ships to use them.

Ferry A vessel that takes cars and people across short stretches of water.

Hovercraft A vessel that moves above the water on a cushion of air. Fans blow air into a “skirt” beneath the ship, where it collects and inflates to lift the boat off the water.

Hull The part of a ship that sits in the water. Inside the hull are decks and vertical walls called bulkheads.

Hydrofoil A speedboat with wing-like structures called foils that generate lift as the boat moves forward. This raises the hull out of the water, reducing its drag.

Hydroplane A fast, streamlined boat that skims across the surface of the water. A hydroplane called the Spirit of Australia holds the water speed record of 511 km/h (318 mph).

Keel A beam along the bottom of a ship’s hull, running from bow to stern.

Lifeboat A small craft kept on a larger vessel in case of emergencies, or a ship launched from land to rescue other ships.

Ocean liner A large vessel used for ocean crossings. Liners are built to withstand rough seas and provide luxury quarters.

Periscope A device that uses mirrors to see around corners. Periscopes are used on submarines so that the crew can see above the water without having to surface.

Port The left-hand side of a ship when facing forwards, towards the ship’s bow (front).

Powerboat A fast boat with a sharp bow and powerful engine. The hull skims the water at high speeds.

Propeller (full name: screw propeller) A device formed of curved, rotating blades. As the blades spin, water is sucked in around them and pushed backwards. This drives a vessel forwards.

Rudder A hinged, blade-like structure, mounted underwater at a ship’s stern. When it turns, the force of water pushing against it changes the ship’s direction.

Sailing ship A vessel powered by sheets of cloth, angled in order to catch the wind to carry the ship forward. The sails are fitted on one or more tall structures called masts.

Ships Large vessels that carry passengers and cargo across the sea. Boats are smaller vessels designed for use on rivers and canals or in coastal waters. Different types of vessel are categorized by the jobs they do. They include: merchant ships, such as dredgers and cargo ships, military ships and fishing and leisure craft. Many ships and boats are powered by a diesel engine, which drives a propeller.

Starboard The right-hand side of a ship when facing forwards, towards the ship’s bow (front).

Stern The rear of a ship, also known as aft.

Submarine A ship that travels underwater. Submarines use ballast tanks to dive or surface. Large, ocean-going submarines are nuclear-powered, but smaller submarines have electric motors, powered by batteries. On the surface, diesel engines take over.

Submersible A miniature submarine, used for research in the ocean depths or to carry out underwater repairs.

Tanker A large ship designed to transport liquids such as oil or chemicals. The largest modern tankers are up to 380 metres (1250 feet) long.

Trawler A boat that drags large fishing nets behind it.

Tug A small, powerful boat used to push or pull large ships and manoeuvre them in and out of ports. Sometimes called a tugboat.

Yacht A sailing boat used for pleasure or sport. Large yachts are often furnished with luxurious living quarters.

Consultant: Chris Oxlade