Haven approach · A · night · leading line
Voyage 3 of 5 · align the marks. Advanced level, about 3 min. Chart reading. Chart 1 · leading and sector lights.
The situation
The charted leading line is northbound along x = 600 in this fictional world. You are west of the line. Observe the front and higher rear marks and compare with the chart. A weak current sets east. By day you can use the fixed structures; at night their lights define the same line.
How do you approach the leading line?
- Alter to starboard to approach the line, then resume north: An authored track brings the two marks toward alignment.
- Alter to port: Move farther west of the charted line.
- Hold north and assume the lights guarantee the route: Ignore the offset and current.
Answers and explanations
Lookout: Work from the actual geometry and charted approach direction. There is no universal instruction to steer toward the higher light.
The sound answer
Alter to starboard to approach the line, then resume north
You begin west of the line, so an easterly component approaches it. The example resumes north as the marks align; continue monitoring alignment and surrounding traffic.
Why the other options fall short
Alter to port
This moves farther from the leading line in the stated approach geometry.
Hold north and assume the lights guarantee the route
Parallel to the line is not the same as on it. Observe alignment and use the charted approach direction.
Chart 1 · leading and sector lights
The front and rear marks define their charted leading line. Sector colours require the charted bearings and notes; white is not a universal guarantee of safe water.