Pretty soon the RPGs will be replaced by FPV drones. Put an explosive drone into the bridge of a merchant ship and it's going to be a mess. I predict that there will be a growing market for drone defenses on merchant ships such as radio jammers and nets over vital spaces.

Radio jammers only work until they figure out the fibre-controlled drones the Ukrainians and Russian's have been making.

Affordable drone defense is something of an unsolved problem right now.