An example video is posted here: https://www.youtube.com/watch?v=XeZ0nudCqxY
The only overlay tag for direction is labeled as "bearing." "Bearing" is the direction TO something, "heading" is the direction in which the boat (or other vehicle) is pointed, and "course" is the direction the boat is going over the ground (which is what the GPS receiver calculates). Garmin should have properly used the term "course" (or track) instead of "bearing." A disappointing oversight for a company that makes navigation equipment. More on that here: https://en.wikipedia.org/wiki/Course_(navigation).
Also, the GPS course (mislabeled "bearing") has too short of an integration time, i.e., too little damping. This causes the reading to wildly fluctuate in conditions where the camera is moving rhythmically sideways. In my example video, the boat is moving sideways due to "sway" caused by ocean swells. The sway averages to zero over a time period of several seconds, but I cannot set an averaging time to eliminate the fluctuations. I have a handheld Garmin GPS (model 72H) that allows setting an averaging time, and it works quite well at removing the short-time-span errors caused by sway. It'd be nice to have the same feature in the camera.
