The International rules are refered to as COLREGS.

(International rules to avoid collisions at sea or simply Collision Regulations)

In the USA there are the local US Inland Rules. The rules are similar but there are differences.

So there is a line where the rules change. On one side the law is the COLREGS on the other side the US law applies. These lines are called the demarkation lines.

So one has to determine which side of the demarkation line applies to one's current position.

There is an official USCG interactive website for this. The link is from inside this book. There are two apps for the two systems. The apps load from links in this book. The color photos, the videos and numerous useful links are in the app. The app can be loaded on your phone or tablet or computer.