Even if you’re an experienced skipper, it’s not hard to occasionally misjudge the speed of another boat, especially when it’s still a safe distance away.

Rather than make a series of last-second maneuvers, which don’t always work, you can use a hand-bearing compass or binoculars with a hand-bearing compass to asses the risk of collision. If your boat’s speed and heading are constant and the compass bearings are moving forward, the other boat should pass ahead. If the bearings are moving aft, the other boat should pass astern. The farther the bearings move, the farther away the two boats should be when they cross. A series of bearings that remain constant, or nearly constant, indicate that the two boats are converging on a collision course.

More experienced skippers have learned to choose a convenient object on the boat, such as a stanchion or a winch, that lines up with the approaching vessel; if it remains in line with the reference object, the two vessels are on a collision course.

Don’t take chances.

When in doubt, if yours is the give-way vessel, head for the other boat’s stern.

If yours is the stand-on vessel, be prepared to alter course anyway, lest the skipper on the give-way vessel takes the “Uh, I thought we were going to pass…” approach to avoiding collisions.