How do you know they were doing that? other than you believe everything Trump and his people say. What did the interrogations show? You do know those boats cannot go all the way to America, don't you?
The known pattern is the same. A fast boat with far more HP than would ever be necessary for "fishing." A crew of 3 or 4: A pilot, mechanic, and a cappo (enforcer to make sure the drugs are delivered), and possibly a navigator for longer, open ocean, runs. The boat is loaded with cargo and there is no gear aboard for fishing.
The boat goes to high speed, often above 60 kts, the second it sees a helicopter or other potential law enforcement / official government presence near it.
Aside from that, since this is a paramilitary operation and NOT a law enforcement operation, it's the go-fast boat's bad luck to have been spotted because the military isn't there to arrest the occupants, nor serve them a warrant and "bring them to justice." The military is there to blow the fuck out of the water in a totally one-sided combat action.
Too fucking bad for the guys on that boat.
As for "can't go to America..."
There are three types of narcoboats:
Go-fast: These are typically used to move drugs or precursors between local cartel operations. That is, island-to-island. They are needed to get the drugs out of high enforcement areas into low enforcement ones where they can then be forwarded to destinations in the US or Europe.
Go-slow: These try to look and act like fishing boats or other craft that are not drug boats. They are used for the same purpose as go fasts but have more range. A Go Slow might be moving drugs from Colombia to Mexico where they will then be moved into the US by land routes.
Narco subs: These are delivery vessels and have 1,000 + nm ranges. They don't go fast and are designed to be as low visibility as possible. They deliver drugs to the US and Europe.