I'm afraid you're wrong:
"The Coast Guard has law enforcement powers within U.S. waters, which covers more than 95,000 miles of U.S. coastline and extends 200 miles from shore, and on international waters. Coast Guard authority supersedes that of the U.S. Navy in terms of law enforcement."
I hated writing up vessel boarding reports. Forgot about the 200 mile limit. Technically he is fair game upto any other countries claim of authority. The vessel is stateless.