
Naval News reports on the continued threat of remotely controlled explosive motor boats to vessel traffic around Yemen. We have talked about this before, here, here, and here. Historically explosive boats have had some success even against heavily armed opponents.

Heavy Cruiser, HMS York, run aground by her own crew to prevent her sinking, after being struck by two explosive motor boats (Italian: barchini esplosivi) of the Italian Regia Marina assault Flotilla, Decima Flottiglia MAS, Souda Bay, Crete, 26 March, 1941.
There was, of course, the suicide attack on USS Cole.

The semi-submersible ship M/V Blue Marlin carrying damaged USS Cole. 31 October 2000. U.S. Navy photo by PH2 Leland Comer.
As I have noted before, remote controlled attacks could be planned and carried out relatively easily using readily available remote control devices and remote viewing systems in wide spread use.
Will we see these threats emerge in the US, or perhaps in the Persian Gulf where they might be encountered by PATFORSWA?
Any number of platforms might be used as the basis for this type of threat from shrimp boats to jet skis. It would be advantageous to the attacker, if they could blend in with local traffic.
Off shore, in SW Asia, the Houthi typically control the attack boat from another boat, within line of sight radio range of the remote controlled boat, but in a US harbor it might be controlled from shore.
If the threat is against a moving target, soft kill systems designed to counter Unmanned Aircraft Systems (UAS) should be equally effective, but they might not work against a threat targeting a fixed point like a moored vessel. Hard kill systems might work as a defense, but it raises the question, how close do you want to get, since the operator could presumably detonate the charge at any time? Success with a 7.62mm machine gun might require a lucky shot to take out a critical component.

Explosive motor boat of the type used by the Israeli Navy in the Independence War, in the Clandestine Immigration and Naval Museum, Haifa, Israel. Possibly an Italian MTM (Motoscafo da Turismo Modificato). Photo from Wikipedia Commons. User:Bukvoed.
How to handle this sort of threat is squarely in the Coast Guard’s “Ports, Waterways, and Coastal Security” mission wheelhouse. Hopefully we are putting some thought into it.