One of the most confusing things about determining legal issues associated with maritime activities is that waterways may have different laws depending on the location.
An important point is to understand if a legal issue came up when the vessel was in U.S. waters or in international waters. The location of the waters and the vessel will determine the applicable laws in many cases.
ShareAmerican explains the general definition of international waters is anything that goes beyond 12 nautical miles from the coast.
When it comes to enforcing laws, the lines can blur a little. Countries have the ability to impose their laws up to 24 nautical miles from land. In addition, countries typically maintain control over their vessels even in international waters.
It is possible for a country to impose its laws on the owners or crew of a vessel even if it is no longer in the waters under the control of that nation because it still has jurisdiction over the boat.
Maritime law can be quite confusing because of the blurred lines when it comes to jurisdiction. Even within the U.S., there are often clashes between state and federal maritime laws that may need ironing out if a situation comes up.
Still, if the owners and crews of vessels follow U.S. and state laws, they can generally stay out of trouble and avoid issues with any entity that may lay claim to the waters in which they are sailing their vessel. So, the idea of international waters or the high sea may be less of an important point than it seems.