“Red Right Returning”
When two ships approach each other bow-on (that’s the front of the ship), each will see the red running light to their right. Which if my spatial reasoning hasn’t failed me, means that they’re on the left (port) side of the ship.
Red Right Return actually refers to returning to harbor or marina. The red channel navigation markers and lights will be on your right.
And not quite; the boat mounted lights indicate to the other boat who has right of way.
For two powerboats crossing, the one on the right has right of way, and they will see (are given) a green light on the other boat.
While the other sees red, like a matador’s cape, which tells it to yield. (which doesn’t work for bulls and just makes them angry because they are color blind)