A question for our captains and navigators

[Bergwind]

Last time I uploaded many pics from the Workington harbour. I have not seen so many lights and daymarks in such a small space. How to use the lights and daymarks?? What is useful for navigation ? What is superfluous ? Why so many lights?

[mitko]

It seems Middle range lights indicate center of the approach channel and daymarks - south and north edge of it so for the vessel it would be clear which side of the channel she is now. Basically if you see from the bridge any of the side marks inline - means you exactly on the edge and likely need to turn vessel back to center.