Boat Navigation

Navigation is an ancient art that is used to determine your current location on planet Earth and to predict where you will be in the future. Traditional navigation uses paper charts that accurately reflect the depth of the water along with land contours. Before a trip, the navigator plots a course on the chart that the boat should follow. During the trip, the navigator plots the position of the boat on the chart and compares the plotted position with the planned one.

Traditional Navigation

Before the invention of instruments that could accurately measure Latitude and Longitude, navigators used a few simple instruments to calculate their location. These included a compass, a log (which measures speed through the water), and a depth sounder. For coastal navigation, these instruments and the knowledge of how to use them provide a reasonably accurate way to determine where you are. Combining this with visual observations (e.g., relative fixes, running fixes, or the height of mountains on land) increases the accuracy.

Global Positioning System

One of the biggest changes in navigation was the introduction of the Global Positioning System (GPS). The GPS system consists of a series of satellites that were launched by the US military to provide three dimensional locations anywhere in the world. This system was also made available for non-military use and commercial manufactures were quick to create products that could identify exactly where you were on the planet.

A GPS unit can be purchased for a few hundred dollars, fit in the palm of your hand, and provide accuracy within a few hundred feet. Most units allow you to enter waypoints (a specific Lat/Long position that you associate with a name) and a route (connecting several waypoints together). GPS units can also show whether a boat is on course to the next waypoint, accurate speed over the ground, and other measurements that make navigating easier. But a GPS is only as good as the navigator that is using it.

Chart Plotting

The logical extension of traditional navigation, GPS, and modern technology is chart plotting. With the speed of modern computers it is feasible to digitize charts. By combining computing resources, GPS, and digitized charts it is possible to create real-time plotting of a boats position on a digital version of the chart.

On Dragonsinger, we will have two different types of chart plotters. One will be a dedicated Raytheon unit and the other will be a sophisticated Windows program running on one of the computers on board. We will comment on the difference between the two once we have more experience. But no matter what happens we will always be prepared to navigate with paper charts, a compass, and a simple log. Technology may make things easier, but you don't want to completely depend on it to insure that you can get to where you want to go.