Step 1 in making a cheat sheet on shapes, lights, and sounds You will see that down the left side of a sheet of paper I listed the various classes of vessels for which the COLREGS give specific shapes, lights, or sounds. 

In the diagram, the classes in Rule 18 (Pyramid of Privilege) are listed first, using abbreviations, from most to least privileged: Not Under Command, Restricted in Ability to Manoeuvre, Constrained by Draft, Fishing, Sailing, Power-driven. Below Power-driven is towing, since, in a sense, it is a special type of power-driven vessel gets some lights and shapes for the type or size of tow. 

I did not bother with seaplanes. And CBD are specially mentions in Rule 18 keeping away from NUC and RAM, but others to keep clear of CBD. 

At the bottom, I added some "funnies": Hovercraft, Submarine, and Wing in Ground Effect platform. Note that subs do not get special lights under COLREGS, but the Canadian and American navies by their internal regulations specify lights that should be used when on the surface. 

Last modified: Sunday, 24 January 2021, 5:19 PM