Vessels sailing around the United States of America have two different sets of rules to deal with, the international Collision Regulations and the Inland Rules. Fortunately these rules never apply at the same time, we switch rules when crossing the ‘COLREGs demarkation lines’.
Why have both 72 COLREGs and Inland Rules?
Inland waters are often a lot more complicated that open sea. For this reason the international regulations allow ‘an appropriate authority’ to create ‘special rules’ – Rule 1(b). USA inland water ways have lots of ‘special rules’ and together they are called the ‘Inland Rules’. Some Inland Rules are identical to the international COLREGs, for example Rule 5 – Lookout is exactly the same. In situations where the international COLREGs do not cover national requirements the Inland Rules provided further, often more specific, guidance.
What are 72 COLREGs?
The United States Coast Guard Navigation Rules refers to 72 COLREGs. Many people know these rules as International Rules or International Rules for Preventing Collision at Sea (IRPCS). The 72 refers to 1972 the year in which the international convention was signed, ratifying the regulations.
Which rules do I need to know?
Anyone in charge of a vesselThe word 'vessel includes every description of water craft, including non-displacement craft, WIG craft and seaplanes, used or capable of being used as a means of transportation on water'. in USA Coastal Waters must understand both International and Inland rules. The COLREGs demarcation lines are close to the coast and can easily be crossed by any size of vessel. Understanding which rules apply in your current position is very important to keeping a vessel safe. Those studying for professional maritime qualification in the USA are required to a pass a test that examines both sets of rules.
How can I find the difference between the rules?
The USCG Navigation Rules layout both International and Inland Rules and is the authoritative document. To help mariners spot these difference with have highlighted the Inlands Rules that are different from the COLREGs. You can find and example here , Rule 1 – Application (USCG Inland Rules)