The pirates jump the ship at night!
With the lights onboard the ship light, a small skiff is invisible and silent compared to the sound of the ships engines. The skiff is faster than the fully loaded ship so they just pull along side, throw a hook up over the railing, and take control.
Banks will hire Brinks for armed security to deliver $10K.
You have a multi-million vessel out there loaded with how much in goods, and they don't use armed security. It's crazy.