The terms, course, bearing and heading, seem to cause confusion among students just learning to navigate. Although, it’s possible to navigate without knowing the meaning of each term, having a common language allows us to discuss navigation more effectively. While I’m sure that you could come up with a rhyme to help you learn these terms, I think it’s best just to take time to memorize and internalize the meanings.
A course is your planned paddling route. It’s usually marked on a map, although you can also just make a mental note. A course can be a straight line going from your point of departure to your destination, or it might consist of two or more legs. An example course shown in the above image starts in Washington Harbor, turns to the northwest corner of Rock Island and crosses to the South Bay of St. Martin Island. See the full chart here.
A bearing is the direction from your location to any distant point given in degrees from north. If you point your compass at a distant lighthouse and the compass reads 56 degrees, then the bearing to the lighthouse is 56 degrees. Read bearings in either true or magnetic.
In most parts of the world magnetic north, the direction your compass points, is not equal to true north, the direction to the north pole. Because, charts are aligned to true north, you must translate any bearings you take with your compass to true north before you can transfer them to a map, and you must adjust any course bearings taken from the chart to magnetic north. To do this, find the chart’s compass rose. It shows the variation from magnetic north to true north. If the variation is west, you add the degrees of variation to the true bearing to arrive at magnetic and you subtract the degrees from magnetic to arrive at true. If it’s east variation, you do the opposite.
The course bearing is the bearing you’ll follow to stay on a leg of a course. For example, the course bearing from “B” to “C” is 71 degrees true and 75 degrees magnetic. The course bearing from “C” to “D” is 30 degrees true and 34 degrees magnetic. To follow a bearing, point your kayak so your compass reads the course bearing and then paddle while keeping your compass pointed at that bearing. When marking a course bearing on your chart, you can mark true, magnetic or both. Stay consistent or label the bearings. You can also mark a back bearing, which is the bearing to take if traveling the course in the opposite direction. The back bearing is always 180 degrees away from your bearing. While marking bearings on your chart, adding distance saves time later.
Your heading is the direction that your canoe or kayak is pointing. When traveling a course, your heading usually is the same as the course bearing, but it doesn’t have to be. In some situations, like when you’re dealing with wind or current by ferrying, your heading may vary from your course bearing while still staying on course. For example, during the 4.7 mile crossing from “C” to “D,” a northwest wind or current is pushing us off our course. If we get too far off course, we’ll end up in the St. Martin shoals, which we want to avoid. To compensate for the wind or current we turn into it and paddle at an angle to our course bearing. We adjust our heading until we are traveling along the course bearing. In the example, our heading is 343 degrees magnetic. That angle counteracts the wind and allows us to stay on course. Our direction of travel is the same as the course bearing.
I can’t recommend the Fundamentals of Kayak Navigation enough. It’s the best book aimed at kayak and canoe navigation on the marker. You should get a copy.