Somehow, we''ve slipped into talking about running
lights as tho'' they are the key indicator re: potential collision with ships. As was just stated, running
lights ''disappear'' on some large ships, especially cruise ships or ships with many working
lights.
The key indicator for the potential collision with a ship is its range
lights: they are high up, not confused with work
lights, and give an immediate indication of approx. direction of travel. OTOH, when you must depend on running
lights, the vessel is usually moving more slowly (e.g. sailboat under sail) and time isn''t so critical.
When ALL
lights are difficult to see due to decreased viz, we discover the primary reason in this
GPS age for having
radar: target detection, electronically.
Jack