There is nothing quite like watching sparkling stars and bright constellations while you drift across the water in your boat. Stargazing from a boat is relaxing, entertaining and awe-inspiring — but it can also be useful. By observing the position of stars in the sky, you can find your bearing in unfamiliar waters and navigate strange seas. Star navigation has been used by seafarers for centuries and is a useful skill for any boater to know. Let’s explore the art of navigating the ocean using stars.
Hundreds of years ago, early navigators traversed the open ocean using only their eyes and the stars. These first seafarers tracked the movement of stars across the night sky and knew the positions of constellations during every season. Their extensive knowledge of celestial bodies allowed mariners to cross large spans of open water with confidence. However, as civilizations advanced, new navigational tools and equipment replaced celestial navigation. Modern seafarers can navigate with great accuracy using Global Positioning Systems (GPS), radar and other technologies. When boats are now equipped with advanced navigational systems, why should seafarers learn to navigate by the stars? Here are a few reasons to preserve the ancient art of star navigation:
Despite modern innovations that allow for highly accurate navigation, navigating using stars remains a valuable and enjoyable skill. When you know how to navigate using the stars, you can always find your way home on a starry night.
Throughout history, mariners have used many different techniques to navigate the ocean using stars. Here are some basic steps for star navigation in each hemisphere:
Celestial navigation relies heavily on the position and movement of the constellations. Constellations are groupings of stars that create recognizable patterns in the sky. As Earth orbits around the sun, these star patterns shift in the sky, making different constellations visible during different seasons. Some constellations, called circumpolar constellations, remain visible all year long in the hemisphere where they are located. Because circumpolar constellations never rise or set, they provide reliable reference points for astronavigation. Knowing the circumpolar constellations in each hemisphere allows navigators to find their way using only the stars. Here is a brief overview of the primary constellations in the Northern and Southern Hemispheres that are used for star navigation:
The ability to identify these important constellations is the first step towards navigating by the stars. Once you can find the navigational constellations in your hemisphere, you can then calculate your boat’s bearing.
Since the first mariners braved the open ocean, the North Star has served as a reliable beacon to guide them home. The North Star, also called Polaris, is located almost directly above the North Pole and does not change position in the sky. The North Star moves in a very small circle above the north celestial pole, while all the other stars in the Northern Hemisphere rotate around it. Because Polaris appears stationary in the night sky, seafarers can easily find true north by locating the North Star. Depending on which constellations are visible in the sky, mariners can use a few different methods to find the North Star:
Once you find the North Star, drop your gaze to the horizon directly below Polaris in the sky — this will be due north.
Because the North Star is only visible from the Northern Hemisphere, mariners boating south of the equator use another technique for navigating by the stars. Although the Southern Hemisphere does not have a bright pole star to follow, seafarers can still locate the south celestial pole using the Southern Cross. At latitudes farther south than 35 degrees south, the Southern Cross can be seen year-round at every hour of the night. No matter the time of year, the Southern Cross reaches its highest point in the night sky when it is pointed due south. At its apex, the Southern Cross will stand perfectly upright over the horizon with the long part of the cross pointing straight down and towards the south celestial pole. However, when the Southern Cross is not at its highest point in the sky, finding south requires a bit more calculation. Follow these steps to find due south using the Southern Cross:
Another more accurate method for finding south in the Southern Hemisphere uses the constellation Centaurus along with the Southern Cross. Centaurus is located next to the Southern Cross and has two bright pointer stars that make up the front leg of the centaur. These pointer stars, called Alpha Centauri and Beta Centauri, can easily be spotted in the southern sky and used to help locate the south celestial pole. Follow these steps to steer your ship south using Crux and Centaurus:
With careful observation and calculation, mariners in the Southern Hemisphere can find their bearing.
Once you have located due north in the Northern Hemisphere or due south in the Southern Hemisphere, finding east and west is simple. Stand facing directly north or south and stretch your arms out straight to each side. When facing north, your left arm points west and your right arm points east. When facing south, your right arm points west and your left arm points east. When traveling close to the equator, Orion also helps mariners find east and west. Orion rises in the east and sets in the west, with the rightmost star on Orion’s belt rising and setting within one degree of true east and true west every day. This star, called Mintaka, rises and sets first of the three stars on Orion’s belt. To use this method of identifying east and west, marine navigators must pay close attention to the movement of this constellation.
Mariners in the Northern Hemisphere can measure their latitude, or position north or south of the equator, based on the height of the North Star in the sky. The angle of the North Star above the horizon will be the same as your boat’s latitude. Seafarers can measure latitude most accurately using tools like a sextant or quadrant, but latitude can also be estimated using only your hands. Extend your arms and make fists. Measure the distance between the horizon and the North Star by placing your fists one over the other. Each outstretched fist measures about ten degrees latitude. The same method can be applied in the Southern Hemisphere using the south celestial pole. First find the south celestial pole using the Southern Cross and Centaurus, and then measure the distance from the south celestial pole to the horizon with your fist. While this method will give only an estimate of latitude, it can prove valuable when navigating by stars without any tools or charts.
A savvy marine navigator knows that finding your bearing and latitude is only half the battle. To navigate on open waters, seafarers must also know their longitude, or their position east or west of the prime meridian. Unfortunately, longitude is extremely difficult to determine using the stars alone. Some early navigators may have calculated their longitude by tracking the movement of rise and set stars across the sky. By recording the position of a specific rise and set star every night at the same exact time, mariners could get a rough idea of how far they had traveled west or east the previous day. Star positions must be recorded every day of a journey, beginning with the known longitude of the location where the voyage began. This method of calculating longitude required careful record-keeping and was still prone to costly miscalculations. Luckily, innovations in marine navigation have made it possible to accurately and easily calculate longitude. Modern seafarers now use chronometers, charts and GPS to determine their exact position on the seas no matter where they are in the world.
Although it is possible to navigate by the stars using only observation, there are several resources available to make celestial navigation easier and more accurate. Here are two of the primary resources for star navigation:
By using these resources and keeping your eyes on the night sky, you can learn to navigate accurately using stars.
If you want to try your hand at navigating by the stars, you can head out confidently in your Formula boat with the knowledge that your reliable navigation system is always there to back you up. If you find yourself heading the wrong direction, the advanced GPS in your Formula boat can get you back on track right away. Formula Boats are built with the best equipment and materials to provide a safe and luxurious boating experience. When you purchase a powerboat from Formula Boats, you’ll enjoy beautiful styling, exceptional performance and a powerful engine — as well as your choice of top-notch navigation systems. Formula powerboats are fully customizable with a variety of features available to suit your boating style. If you’re ready to experience the boating like never before, contact Formula Boats to learn more about our premier powerboats.