In Texas the State has jurisdiction out 3 miles. If you are more that 3
miles offshore you are out of the state, but the line for the US goes out
into the Gulf of Mexico until it borders Mexican waters and that is........
not sure exactly, but over 150 miles offshore. The US / Mexican border runs
straight out from where the Rio Grand river spills into the Gulf of Mexico.
I know, because I commercial fished along the line 20 years ago and Mexican
gun boats ran along the line looking for boats that floated across that line
staying by their fishing gear as it drifted. They would confiscate your
boat, gear, crew and you and throw you in jail, until your family could pay
some ungodly $200,000 fine or more, depending on how nice your boat was and
how much they thought your family might have. I would have rotted there.

Not sure how far it extends out in the Atlantic or Pacific. I know there are
no international water in the Gulf of Mexico though.

Sea Yawl,
John