past experience paints a profile, this one fit it quite well
a "go fast" boat - check. visual surveillance confirms a cargo - check. cargo is packed like many other previous boats that were carrying drugs - check. and of course,
it moving, acting, and quacking like a duck.
i would not be surprised if there is humint reporting boat departures, along with other methods of intel collection. not much happens in the gulf without the us knowing about it if the us having an interest in monitoring things. in short, it's not exactly rocket science to figure out it's a drug boat.