Buoy in the context of Navaids

A navigational aid (NAVAID), also known as aid to navigation (ATON), is any sort of signal, markers or guidance equipment which aids the traveler in navigation, usually nautical or aviation travel. Common types of such aids include lighthouses, buoys, fog signals, and day beacons.

A fishing float or bobber is a lightweight buoy used in angling, usually attached to a fishing line. Angling using a float is sometimes called float fishing.

A mooring is any permanent structure to which a seaborne vessel (such as a boat, ship, or amphibious aircraft) may be secured. Examples include quays, wharfs, jetties, piers, anchor buoys, and mooring buoys. A ship is secured to a mooring to forestall free movement of the ship on the water. An anchor mooring fixes a vessel's position relative to a point on the bottom of a waterway without connecting the vessel to shore. As a verb, mooring refers to the act of attaching a vessel to a mooring.

The term likely stems from the Dutch verb meren (to moor), used in English since the end of the 15th century.

The International Boundary Commission (French: Commission de la frontière internationale) is a bi-national organization responsible for surveying and mapping the Canada–United States border and regulating construction close to the border. The commission was created in 1908 and made permanent by a treaty in 1925.

Its responsibilities also include maintaining boundary monuments and buoys, keeping the border vista on each side clear of brush and vegetation within three meters (about 10 feet) from the boundary, overseeing any applications for permission to build within the vista, and reporting annually to the governments of both countries.

Yacht racing is a sailing sport involving sailing yachts and larger sailboats, as distinguished from dinghy racing, which involves open boats. It is composed of multiple yachts, in direct competition, racing around a course marked by buoys or other fixed navigational devices or racing longer distances across open water from point-to-point. It can involve a series of races with buoy racing or multiple legs when point-to-point racing.

A speargun is a ranged underwater fishing device designed to launch a tethered spear or harpoon to impale fish or other marine animals and targets. Spearguns are used in sport fishing and underwater target shooting. The two basic types are pneumatic and elastic (powered by rubber bands). Spear types come in a number of varieties including threaded, break-away and lined. Floats and buoys are common accessories when targeting larger fish.

A lobster trap or lobster pot is a portable trap that traps lobsters or crayfish and is used in lobster fishing. In Scotland (chiefly in the north), the word creel was used to refer to a device used to catch lobsters and other crustaceans. A lobster trap can hold several lobsters. Lobster traps can be constructed of wire and wood, metal and netting, or rigid plastic. An opening permits the lobster to enter a tunnel of netting or other one-way device. Pots are sometimes constructed in two parts, called the "chamber" or "kitchen", where there is bait, and exits into the "parlor", which prevents escape. Lobster pots are usually dropped to the sea floor, one or more at a time, sometimes up to 40 or more, and are marked by a buoy so they can be picked up later.

A day beacon (sometimes daybeacon) is an unlighted nautical sea mark. A signboard identifying it is called a day mark. Day beacons typically mark channels whose key points are marked by lighted buoys. They may also mark smaller navigable routes in their entirety. They are the most common navigation aid in shallow water, as they are relatively inexpensive to install and maintain. Navigation around them is similar to that around other navigation aids.

Weather buoys are instruments which collect weather and ocean data within the world's oceans, as well as aid during emergency response to chemical spills, legal proceedings, and engineering design. Moored buoys have been in use since 1951, while drifting buoys have been used since 1979. Moored buoys are connected with the ocean bottom using either chains, nylon, or buoyant polypropylene. With the decline of the weather ship, they have taken a more primary role in measuring conditions over the open seas since the 1970s. During the 1980s and 1990s, a network of buoys in the central and eastern tropical Pacific Ocean helped study the El Niño-Southern Oscillation. Moored weather buoys range from 1.5–12 metres (5–40 ft) in diameter, while drifting buoys are smaller, with diameters of 30–40 centimetres (12–16 in). Drifting buoys are the dominant form of weather buoy in sheer number, with 1250 located worldwide. Wind data from buoys has smaller error than that from ships. There are differences in the values of sea surface temperature measurements between the two platforms as well, relating to the depth of the measurement and whether or not the water is heated by the ship which measures the quantity.

The Île de Sein [il də sɛ̃] is a Breton island in the Atlantic Ocean, off Finistère, eight kilometres from the Pointe du Raz (raz meaning "water current"), from which it is separated by the Raz de Sein. Its Breton name is Enez-Sun. The island, with its neighbouring islets, forms the commune of Île-de-Sein in the Finistère department of Brittany in north-western France. Inhabitants of Île-de-Sein are called in French Sénans.

Lying on the sea routes going south from the English Channel, Sein is well known for the dangers of its waters, the Chaussée de Sein, a vast zone of reefs stretching more than 30 miles from east to west, requiring numerous lighthouses, beacons, and buoys. The lighthouses near the reef include Ar Men, La Vieille and Tévennec.

Provincetown Harbor is a large natural harbor located in the town of Provincetown, Massachusetts. The harbor is mostly 30 to 90 feet (9 to 27 m) deep and stretches roughly 1 mile (1.6 km) from northwest to southeast and 2 miles (3.2 km) from northeast to southwest – one large, deep basin with no dredged channel necessary for boats to enter and exit.

A tall green buoy east of Long Point (i.e., the tip of Cape Cod) marks the entrance to Provincetown Harbor from Cape Cod Bay.

A surface marker buoy, SMB, dive float or simply a blob is a buoy used by scuba divers, at the end of a line from the diver, intended to indicate the diver's position to people at the surface while the diver is underwater. Two kinds are used; one (SMB) is towed for the whole dive, and indicates the position of the dive group throughout the dive, and the other, a delayed surface marker buoy, DSMB or decompression buoy, is deployed towards the end of the dive as a signal to the surface that the divers have started to ascend, and where they are going to surface. Both types can also function as a depth reference for controlling speed of ascent and accurately maintaining depth at decompression stops. Surface marker buoys are also used by freedivers in open water, to indicate the approximate position of the diver when submerged. They may also be used to support a catch bag or fish stringer by underwater hunters and collectors. A DSMB is considered by recreational scuba divers and service providers to be a highly important item of safety equipment, yet its use is not part of the entry level recreational diver training for all training agencies, and there are significant hazards associated with incompetent use.

A "safety sausage" or "signal tube" is a low volume tubular buoy inflated at or near the surface to increase visibility of the diver in the water. A DSMB can be put to this service when necessary. When used by a diver to indicate their position, any of these may be described as a personal marker buoy.