Transits and Leading Lines

A transit occurs when two fixed objects are in line as seen from the vessel. When two charted objects are in transit, you know you are on that line of position. Leading lines are transits specifically set up to guide vessels along a safe channel — they often use marks or lights ashore.

Transits are extremely valuable for pilotage because they provide a precise line with no instruments needed. They can confirm your position, guide you along a safe track, or warn you if you are drifting off course.