These shapes are used as required by the collision regulations to indicate that the vessel is "Restricted in her ability to Manouver" or "RAM". As I have been spending most of my evenings in the US gulf doing lightering operations. As a master, it feels inherently bad to wear these shapes on my halyards, because it means that I can't take my ships anyway I want to. Adn when your 200 meters plus vessel is manouvering at distances of 20 meters from a 300 meters long ship, the last this you want to do is go any closer. I find the manouvering for this fascinating because the dynamics of working such large vessels is amazing to watch unfold. Maybe we'll have beer one day and I'll explain the hydrodynamics on paper napkins.
In the meanwhile, observe the balls.
