There is s conflict between merchant ships being generally forbidden under international maritime law from carrying weapons, and how to deal with the the upsurge of pirates.

One interesting solution is the electronically controlled water cannon, which comes with a remote control joystick, so that the operator can be away from the turret, and the returned fire, an automatic system to track small boats, the ability to also shoot pepper spray, and, at 5000 liters a minute, it can, “send an 85 kg barrel flying end over end at 75 meters”, which is well probably at the accurate fire limit for someone shooting you at a small boat.

Best of all, it’s not a weapon, it’s “fire fighting equipment,” and so is not subject to things like port restrictions.