Just a heads up that a friend of mine worked in this direction for years but was rejected from a captain's license because he had that partial color-blindness thing lots of people have, and that reportedly was enough to disqualify him permanently. Most of a decade "wasted" (if wasted is defined as sailing yachts around the Med and picking up languages). He now sells wines in Sydney, with the benefit of correct pronunciation in four or five languages.
That's really interesting - makes sense, however as the main nautical colors are red and green. Messing them up would mean the difference between avoiding a ship and hitting it. Never thought about how bad a color choice that was for lights!
