That chinese ship found that beer bottles full of gasoline worked real well......there is no logical reason to set around with your thumb in your butt and let those animals on board. Plain cheap simple shotguns would work fine. Give the skinnies a face full of buckshot. If you have to, throw the guns overboard before docking. You are out, ???what??? $500 for saving the ship? In this situation, screw the law, save the ship.
Put the shotguns in a waterproof container, then drop ‘em the fresh water tanks or a fuel tank. Or do Customers Inspectors check these?
The law is only good as long as it does not interfere with your right to life, liberty, and happiness.