So how do private security firms do it without getting hamstrung by weapons import restrictions and international treaties? They keep their weapons aboard armoured barges in international waters of course.
The practice of storing large caches of weaponry in international water is popular because it constitutes a legal grey area wherein few countries have laws or abide treaties dictating what is allowed 19km out to sea -- whether it's enough guns to take over Somalia or your run-of-the-mill monkey knife fight. The armouries also provide easier access to supplies, allowing security forces to respond more quickly to ships under attack.
Patrol ships will pick up arms when entering dangerous waters, then drop them off again when they complete their patrol. This avoids the need to dock escort ships in foreign ports, some of which, like Egypt and Yemen, are less than thrilled to see armed foreigners on their docks.
These armouries are instead typically located aboard tugs or other small ships and are generally protected by armed guards. According to Thomas Jakobsson of Sea Marshals Ltd, roughly a dozen ships currently act as armouries throughout the world with a half dozen parked in the Red Sea, three more in the Arabian Gulf off the coast of the UAE and a few more off Madagascar.
The business of floating weapons lockers is growing rapidly as more companies invest in protecting shipping lanes and guarding against pirates. However there are few, if any, legal standards governing the practice, "Everything has got to be secured correctly, recorded, bonded, the correct locks and so on. It's not just a case of find a room, put some weapons in it and everybody chill out," said Nick Davis of the Maritime Guard Group. Just nobody tell the pirates about these isolated and lightly-defended weapons caches, we wouldn't want to give them more targets. [NPR via Defense Tech]