What should be done to prevent more ships from being pirated?

[lone wolf]

Laughing. I bet that would cause that device to be obsolete real quick.

They need to start arming these merchants.

Arm the merchants and you get a dhow (?) with a five incher, then torpedoes, then an arms race between merchant and pirate. I think the crews have to be taught how to repel borders. The Navy can't be everywhere ... unless they want to start traveling in convoys.