IMO Collision RegulationsBitmetric Technologies
1.5 Varies with device
The International Regulations for Preventing Collisions at Sea 1972, also known as "COLREGs", "Rules of the Road" or "RoR", prescribe rules to be followed by ships and other vessels at sea in order to prevent collisions between two or more vessels.
The original document is generally published by IMO although countries may publish their own versions.
It is a highly recommended "sea bible" for mariners, sailors, navigators, merchant navy deck officers and deck cadets.