When it comes to navigating your boat on the open sea, there are two primary methods to choose from: great circle and rhumb line sailing. Depending on your experience as a sailor and the specifics of your voyage, one of these techniques may work better for you. Let’s take a closer look at the difference between great circle and rhumb line sailing.
Great circle sailing is based on the shortest distance between two points on a sphere. You may remember this concept from studying geometry in school: the shortest path between two points on a sphere is a curve that follows the circumference of a circle that passes through those two points. This is called a great circle.
Great circle sailing takes advantage of this principle to plot the shortest route between two points on the surface of the Earth. If you were to draw a straight line between two points on a flat map, it wouldn’t follow the shortest path on the Earth’s curved surface. But by plotting a great circle, you can ensure that you’re taking the fastest possible route.
Rhumb line sailing, on the other hand, is based on following a constant compass bearing. This means that your boat will follow a straight line on the map, with each degree of longitude crossed at the same angle. Rhumb line sailing is simpler to plot and follow than great circle sailing, but it may not always result in the shortest route between two points.
When deciding which method to use, it’s important to consider a few factors. Great circle sailing is more accurate for longer voyages, especially those that involve crossing different latitudes. It can save you valuable time and fuel, especially if sailing conditions are challenging. However, it can also be more difficult to plot and follow, especially if you don’t have access to computerized navigation tools.
Rhumb line sailing is a great choice for shorter journeys or for novice sailors who are still getting comfortable with navigation. It doesn’t require as much skill or calculation, and can still get you to your destination with reasonable accuracy. However, if your voyage involves crossing different latitudes or navigating through crowded areas, you may want to consider using great circle sailing instead.
In the end, the choice between great circle and rhumb line sailing comes down to your individual needs as a sailor. Whichever method you choose, make sure to plan your voyage carefully and stay aware of the conditions around you. With the right skills and tools, you can chart a course that takes you anywhere you want to go.