Search results
Results from the WOW.Com Content Network
They are also known as fairway buoys and clear water buoys. They are recognisable by their red-and-white vertical stripes and commonly bear a top sign in shape of a red ball. They either flash Morse code "A" (di-dah), or one long flash, occulting (more light than dark) or isophase (equal light and dark) every 10 seconds (L Fl 10s).
A cardinal mark is a sea mark (a buoy or other floating or fixed structure) commonly used in maritime pilotage to indicate the position of a hazard and the direction of safe water. Cardinal marks indicate the direction of safety as a cardinal ( compass ) direction ( north , east , south or west ) relative to the mark.
A lateral buoy, lateral post or lateral mark, as defined by the International Association of Marine Aids to Navigation and Lighthouse Authorities, is a sea mark used in maritime pilotage to indicate the edge of a channel. Each mark indicates the edge of the safe water channel in terms of port (left-hand) or starboard (right-hand).
Marks are shown on nautical charts, using symbols that indicate their colour, shape and light characteristic, and are usually identified by name or number. In a wider sense the phrase "sea mark" is often understood to include all types of landmarks, structures and devices that can be used to provide warning and guiding signs to mariners.
Where a channel divides the mark at the junction is called a "preferred channel mark" or "junction buoy". The mark has the colour and shapes corresponding to the preferred channel with a band of the other colour to indicate it is the other hand mark for the subsidiary channel. [1]
Graphical and textual descriptions of navigational light sequences and colours are displayed on nautical charts and in Light Lists with the chart symbol for a lighthouse, lightvessel, buoy or sea mark with a light on it. Different lights use different colours, frequencies and light patterns, so mariners can identify which light they are seeing. [1]
big.assets.huffingtonpost.com
Marker buoys, used in naval warfare (particularly anti-submarine warfare) emit light and/or smoke using pyrotechnic devices to create the flare and smoke. Commonly 3 inches (76 mm) in diameter and about 20 inches (500 mm) long, they are activated by contact with seawater and float on the surface.