You know this isn’t true, but continue to assert it. I gave you a link to a non-false flag tanker that was forced away by the Coast Guard and escorted out for several days.
As I explained in my reply, that tanker was not forced away. It lied and said it was headed to the Dominican Republic, but tried to sail to Cuba - presumably to surreptitiously sell oil without triggering retaliatory tariffs. When it realized it was being followed by the Coast Guard, it turned around and sailed to its stated destination.
The ship could have made port in Cuba and unloaded it's oil. But then Colombia would be hit with tariffs. The threat of tariffs made the ship turn around on its own volition, not because the coast guard deployed force to stop the ship.
If the vessels were legally flagged, both of these are indeed actions of a blockade!
You're just ignoring the fact that the ships the US seized were flying false flags and are subject to seizure regardless of the embargo.
And in the case of the Ocean Mariner, the ship wasn't forcibly turned away by the coast guard. They changed course to the Dominican Republic (which was its purported destination anyway...) on their own volition when the realized they were being tracked. The could have continued to Cuba if they wanted to, but that would trigger retaliatory tariffs.
> The Cuban Missile Crisis doesn’t even meet your standard.
Yes it was a blockade! The US military deployed its forces with orders to seize Soviet ships bound for Cuba (though they turned away before any ships were actually boarded).