Even with sanctions, you can still exit legally; the rules are really just for people to play with.

Mars Finance News, May 21 — According to market sources, the United States has granted a license allowing a major ship scrap buyer to purchase four ships that were sanctioned for transporting cargo related to Iran.
This move could open a legal exit route for some ships in the "shadow fleet" used by Iran and Russia to transport sanctioned goods, a fleet that has expanded under Western sanctions.
Ships associated with Iran-related networks will be dismantled and recycled.
U.S. officials stated that this case-by-case licensing approach could be used more broadly to help remove high-risk ships from global waters.