The History of Navigation: From Star Compasses to GPS

Navigation is defined as the science of determining a current location and successfully plotting a course to the next point. Centuries before the global positioning system (GPS) became available for civilian use, mariners used several means of navigation. Navigation was not only a science but, as Arab navigator Ahmad ibn Majid of the fifteenth century proclaimed, it was also an art. Around the globe, Polynesians, Vikings, the Chinese, Arab navigators, and finally an Englishman named John Harrison developed strategies for navigating the oceans.

Long before Europeans happened into the Caribbean Islands at the close of the fifteenth century, Polynesians were colonizing the vast islands of the Pacific Ocean region. The outrigger canoe was possibly developed in Southeast Asia more than 5,000 years ago and used by Polynesians to reach destinations as distant as Samoa (c. 1000 BCE) and Tonga and as remote as Easter Island (after 700 CE) in Oceania. Navigators referred to as wayfinders by the Polynesians carried an image of a star compass in their minds to help them determine position. The star compass consisted of thirty-two equidistant points divided into four cardinal directions; those quadrants were sectioned further into seven points. Navigators employed wave patterns to keep on course. They expanded the target island by observing the flight paths of sea birds and by examining driftwood and other flotsam. Once near a target, the reflection of coastal or lagoon water in the clouds served to fine-tune the final approach. Twentieth-century wayfinder Nainoa Thompson notes that the star compass “is a mental construct to help you memorize what you need to know to navigate.” In 1976, Micronesian Mau Piailug sailed from Hawai‘i to Tahiti using only the timeless image of the star compass learned from his father.

Meanwhile, on the other side of the globe, Viking invasions from the Scandinavian Peninsula into Western Europe began in c. 790 CE; raids continued into Russian territory through the ninth and tenth centuries. Ruins of Viking settlements located as far away as Greenland date to c. 1000 CE. Like Polynesians, Norsemen navigated using their senses to observe the natural world. Sight enabled them to observe the position of the sun during the day and stars by night. Visuals of birds as well as calls of birds in the fog let Vikings know that the shore was near. Watching for whales kept sailors informed of ocean currents and schools of fish, which were both indicators of location. Changes in wind patterns were sensed both by feeling and smell. Norsemen employed plumb bobs to find the depth of surrounding water, another indicator of distance from the shore as well as a means of taking water samples. Brackish water indicated a mixture of ocean water mixed with freshwater, providing another measure of the proximity to land. And like Polynesians, Vikings observed the color of water, which indicated distance from the shore. Some historians debunk the use of the solarsteinn or sunstone as a navigational tool, writing that this device does not appear until the High Middle Ages in literature and not as a reference to a navigational instrument.

Concurrently, the Chinese were in the process of developing the properties of the compass as a navigational tool. During the Han Dynasty (206 BCE-220 CE), a magnetized spoon placed on a disc of bronze served as a means of divination. By the Tang Dynasty (618-907 CE), alchemists magnetized iron needles and floated the needles in water, producing a wet compass, which indicated north. By the time of the Sung Dynasty (9601279 CE), mariners were successfully sailing from China to the Arabian Peninsula aided by this new application of magnetic north.

Arab and Persian navigators quickly combined Chinese technology with a Greek invention from c. 390 CE known as the astrolabe to facilitate trade throughout the Indian Ocean area. The compass indicated north, and the astrolabe equipped navigators with the ability to ascertain latitude. European explorers capitalized on Middle Eastern technology by using the astrolabe and another Arab navigational tool called the kamal to construct the cross staff and back staff, a less cumbersome means of determining latitude.

There is an important factor for deducing position in all of these great navigational methods that is lacking, and that is a way to determine longitude. On July 8, 1714, England issued the Longitude Act offering prizes of varying amounts to inventors who could produce an instrument capable of measuring longitude from half a degree to two-thirds of a degree, and to within one degree of accuracy. A clockmaker named John Harrison produced a contraption called H-1 in 1735; a sea trial from Spithead (a strait in the English Channel) to Lisbon and back commenced, proving that H-1 was capable of producing an accurate read of longitude. After several improvements, Harrison perfected and produced H-5 in 1770. The Board of Longitude requested that an exact copy of Harrison’s watch (later known as a chronometer) be reproduced. Larcum Kendall did so, calling his reproduction K-1. Harrison and Kendall received high praise from Captain James Cook after his second voyage aboard the Resolution to the Pacific Islands; Cook noted that with the help of K-1 he was able to accurately map the South Seas.

Twenty-first-century navigators rely on GPS to pilot ocean-going vessels and airplanes across vast expanses of water. The current GPS includes twenty-four satellites. The first set was launched in 1978; the final set was in place by 1994. These satellites orbit the Earth once every twelve hours. GPS is not failproof. Satellites can be lured back to Earth by gravity. Earth’s atmosphere can distort signals sent from satellites. Tall structures such as overpasses can block signals. Technicians work around the clock to monitor the system. GPS provides latitude, longitude, and altitude, enabling pinpoint accuracy for users. Of course, there is still some wisdom to be found in a question posed by Mau Piailug: “What do you do when all of the paper disappears?” or in this case technology fails.

FURTHER READING:
Forte, Angelo, Richard Oram, and Frederik Pederson. 2005. Viking Empires. Cambridge: Cambridge University Press.

Sobel, Dave. 2011. Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time. London: Harper Perennial.

Thompson, Nainoa. “On Wayfinding.” Hawaiian Voyaging Traditions [archive online]. http:// archive.hokulea.com/ike/hookele/on_wayfinding.html. Accessed March 14, 2018.

The Wayfinders. 1999. Written and produced by Gail K. Evenari, PBS.