The advance of technology has changed the development of, and reliance on, visual aids to navigation but they continue to be vital tools for mariners to assess and verify their position. They provide situational awareness and orientation, indicate current flow and afford redundancy for electronic systems. They also highlight individual dangers such as wrecks, rocks and shoals. The book updates an original report issued in 2003 and evidence compiled during the original consultation and as part of the updating is included.
