News of the melding of two emerging technologies of interest to the Coast Guard.The Navy’s US Fleet Forces command is experimenting with putting “non-lethal” weapons on unmanned surface vehicles.
“Operating in autonomous and semi-autonomous modes, the small militarized boats are equipped to employ a directional acoustic hailer, eye dazzling laser and flash-bang munitions; each non-lethal weapon was carefully-orchestrated to respond to a set of threatening behaviors from intruder vessels.”

Looks like the Navy is actively developing Unmanned Surface Vehicles:
http://www.rolls-royce.com/marine/news/2012/121024_mini_water_jet.jsp
Perhaps they could be used to provide persistent surveillance for drug interdiction.
Demo of a BAE optionally manned RHIB system. https://www.marinelink.com/news/unmanned-rescue-the428973