Just Security has an examination of the various authorities at work in the application of blockades as used in conjunction with the conflict with Iran.
Since boardings are Coast Guard’s bread and butter, you may find it interesting.
They also have a look at the Coast Guard’s peacetime authorities here, “Maritime Law Enforcement on the High Seas: Authority, Jurisdiction, and the Seizure of The Skipper.“
Chuck Hill's CG Blog 
Lack of understanding of U.S. Navy international maritime responsibilities has been driven mostly by politics. Key capabilities like sufficient Carrier Strike Groups, ESCORTS, Amphibious force assets, and elimination of the Navy’s ability to operate & maintain itself . . . has been depleted to the point of irresponsibility. Shrinking the carrier force, not maintaining the Cruisers, and parking (withdrawing from service) our EXCORTS, and elimination of Expeditionary Logistics and Maintenance Activity simply must be reconstituted. This illicit activity has really taken a toll, and we are not done yet. If one cannot maintain one’s self then operations when peer-to-peer combat begins . . . will be brief.
https://www.centcom.mil/MEDIA/PRESS-RELEASES/Press-Release-View/Article/4480820/us-disables-2-more-vessels-violating-blockade-in-gulf-of-oman/
May 8, 2026
U.S. Disables 2 More Vessels Violating Blockade in Gulf of Oman
USCENTCOM
TAMPA, Fla. — U.S. forces disabled M/T Sea Star III and M/T Sevda, May 8, prior to both vessels entering an Iranian port on the Gulf of Oman in violation of the ongoing U.S. blockade.
U.S. Central Command (CENTCOM) enforced blockade measures against two Iranian-flagged unladen oil tankers attempting to pull into an Iranian port on the Gulf of Oman. A U.S. Navy F/A-18 Super Hornet from USS George H.W. Bush (CVN 77) disabled both tankers after firing precision munitions into their smokestacks, preventing the non-compliant ships from entering Iran.
U.S. forces also disabled Iranian-flagged M/T Hasna, May 6, as it attempted to sail to an Iranian port in the Gulf of Oman. An F/A-18 Super Hornet from USS Abraham Lincoln (CVN 72) disabled the unladen oil tanker’s rudder by firing several rounds from a 20mm cannon gun.
All three vessels are no longer transiting to Iran.
“U.S. forces in the Middle East remain committed to full enforcement of the blockade of vessels entering or leaving Iran,” said Adm. Brad Cooper, CENTCOM commander. “Our highly trained men and women in uniform are doing incredible work.”
Multiple commercial vessels have been disabled and more than 50 have been redirected by CENTCOM forces to ensure compliance.