The U.S. Department of the Treasury's Office of Foreign Assets Control (OFAC) announced that several individuals and vessels have been placed on the Specially Designated Nationals and Blocked Persons List (SDN List). This decision is based on their determination that the legal criteria for sanctions were met. As a result, their property and interests in these properties under U.S. jurisdiction are blocked, and U.S. persons are generally prohibited from conducting transactions with them. The listed vessels are associated with entities that are blocked under Executive Order 13902, emphasizing their link to Iranian interests.
Simple Explanation
The government decided that some people and boats did something they shouldn't have, so their stuff is now off-limits, and U.S. people can’t do business with them.