INGENIEUR
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Early Navigational Tools - Water Encyclopedia
Determining latitude can be accomplished relatively easily using celestial navigation . In the Northern Hemisphere , mariners could determine their latitude by measuring the altitude of the North Star above the horizon . The angle in degrees was the latitude of the ship .
Living by the Sea - Conservation International
About 44 % of the world ’ s population live within 150km ( 93 miles ) of the ocean . Some USD2.5 trillion per year of economic value is produced by the ocean . Three out of every seven people in the world depend on seafood as their main source of protein .
Art of Navigation
Maritime Industry
By Pang Soo Mooi
The first Western civilisation known to have developed the art of navigation at sea were the Phoenicians , about 4,000 years ago ( c . 2000 BCE ). Phoenician sailors accomplished navigation by using primitive charts and observations of the Sun and stars to determine direction . Despite these early beginnings , it would take many centuries before global navigation at sea became possible . Until the 15 th century , mariners were essentially coastal navigators . Sailing on the open sea was limited to regions with predictable winds and currents , or where there was a wide continental shelf to follow . Farther ventures were enabled by the development of scientific and mathematical based methods and tools .
Measurement of speed of ship – nomenclature of using log - Wikipedia
All nautical instruments that measure the speed of a ship through water are known as logs . This nomenclature dates back to the days of sail , when sailors toss a log attached to a rope knotted at regular intervals off the stern of a ship . Sailors count the number of knots that passed through their hands in a given time to determine the ship ’ s speed . Today , sailors and aircraft pilots still express speed in knots .
A chip log consists of a wooden board attached to a line ( the log-line ). The log-line has a number of knots at uniform intervals . The log-line is wound on a reel so the user can easily pay it out .
Over time , log construction was standardised . The shape is a quarter circle , or quadrant , and the log-line attaches to the board with a bridle of three lines that connect to the vertex and to the two ends of the quadrant ’ s arc . To ensure that the log submerges and orients correctly in the water , the bottom of the log is weighted with lead . This provides more resistance in the water and a more accurate and repeatable reading . The bridle attaches in such a way that a strong tug on the log-line makes one or two of the bridle ’ s lines to release , enabling a sailor to retrieve the log .
Earliest Navigation Methods - National Geographic
The earliest navigation methods involved observing landmarks or watching the direction of the sun and stars . Few ancient sailors ventured out into the open sea . Instead , they sailed within sight of land in order to navigate . When
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