10 Less Lethal Ways to Stop Small Watercraft

Using the rotor wash of helicopters to convince "go fast" boats is not original and it does come with danger, but it is a proven technique with a fair degree of success.

Long Range Acoustic Device. Already in use afloat as a defensive measure and by a few military and LE agencies for riot control or area denial. It would not be a large change to start using them more offensively. Depending on frequency they will create either noise pain or a more internal "vibratory" discomfort.

These have been used (with little success) by environmental groups vs. whalers, illegal fishers, and polluters. Modern technology could surely do it better.

Sorry. Couldn't resist. During the Vietnam War the US Navy patrol boats were attacked by dumping large quantities into constricted waters where it was not easy to avoid. This fouled the water intake of the jet drives that the boats relied on

Imagine hitting a floating obstacle (like a log). A method could be developed to drop or launch a rigid floating obstacle. The vessel will hit it, take damage, and possibly be disabled or maneuver wildly to avoid and again possibly swamp, lose control or otherwise stop.

Again, we are aiming at fouling either the hull or the water intakes. This could be dropped or sprayed from both air and surface vessels.

We could make an attempt to pay the boat crews to abandon both the load of contraband and the boat. While this may work while underway, it would be best if our operatives could complete the payment before the vessel launched but after it was loaded. (Not always possible, I know).

Another tried and true technique that requires surface vessels to maintain close parallel course and speed. If you upgrade from firefighting water monitors to weaponized high-pressure water jet that would have the ability to directly impact outboard motors or navigational equipment.

The aerial version of #9

By far the hottest part of any vessel will be either the engines or the exhaust. Non-explosive kinetic rounds could be targeted AND guided directly to the powerplants of vessels.