When Stars Become Satellites: Navigating and Science

While the ship had its own GPS system for navigation, the 38th voyagers relied on a handheld device for recording latitude and longitude. Source: Wikimedia Commons

It is 11:00 am on the morning of May 17, 2014, and the first piece of information to christen the scientific logbook is the most basic and perhaps the most critical: Latitude ºN: 41º17’58.1″, Longitude ºW: 72º01’15.4″. As the Morgan travels from Mystic to New London, where she will pick up additional ballast to properly weight her for her journey to deeper waters, her coordinates are a necessary part of the scientific data collection conducted by the voyagers. Each of them is trained in the operation of a handheld GPS device (Global Positioning System), which will allow them to mark exactly where their observations take place.

For the purposes of navigation during the 38th Voyage, the Morgan has also been outfitted with a larger GPS system. Today, during the first leg of the journey, such equipment is less crucial for Captain Kip Files and his crew—they can steer according to landmarks easily viewed from the helm. However, when the ship sails further offshore, the GPS will provide information on the Morgan’s position that allows the crew to direct her toward her next destination.

The GPS system relies on satellites to provide information on position, speed, and time. Source: Wikimedia Commons

The 38th Voyage may mark the first time that twenty-first century navigational equipment has found a home on a nineteenth-century vessel. This satellite-based system first became available in 1993 and uses a system of twenty-four satellites to determine position, speed, and time. It has a variety of terrestrial applications, and can now be found in most cars and phones. At sea, however, without access to the resources available on land, navigation is both more important and more challenging. A GPS can provide immediate and accurate information on speed, position, and heading to ensure that the vessel reaches its destination in the safest, most economical, and timely fashion.

Sailors have always recognized the importance of determining a ship’s position, though without modern technology, their methods of doing so were much more extensive. From the seventeenth to the twentieth centuries, celestial navigation was the primary source for measuring coordinates; that is, latitude (the distance north or south of the equator) and longitude (the distance east or west of the prime meridian). This process involved aligning a celestial object, such as the moon or a constellation, with the horizon. The distance was measured using a sextant and then applied to mathematical tables to calculate one’s position accordingly.

Modern sailors are still required to possess a basic understanding of a sextant while at sea. Source: Mystic Seaport

The difficulty with celestial navigation lies in its inherent dependence on weather conditions and clear skies, in addition to the potential for human error in the mathematical calculations. However, while a GPS can provide instant coordinate measurements, historical practices are far from obsolete. There are cases in the modern era in which a loss of electricity onboard requires the use of celestial navigation, a skill that merchant mariners are still required to possess. In fact, voyager Frank Reed demonstrated his knowledge of the sextant while searching for whales on Stellwagen Bank during a later stretch of the Morgan’s journey. Still, instruments like the GPS have shown how modern technology can be used in a variety of ways in the marine environment, aside from navigation: mapping hazards, tracking fishing migrations, underwater surveying, and of course, marking areas of scientific interest. Most importantly, as the voyagers demonstrate, the GPS program is free, open, and user-friendly, allowing for citizen science at literally the touch of a button.

The Morgan’s position, as determined by latitude and longitude, was the first piece of information recorded in the logbook at every hour. Source: Lisa Gilbert