back when piracy was rampant in the Straits of Malacca, and the pirates soon learned to leave them alone. But most companies find it cheaper to pay ransom occasionally than to buy weapons and continuously train crews to use them. Most weapons are expensive, require constant maintenance and training to be effective, and it means a lot of paperwork when you go into foreign ports who take a dim view of armed civilians steaming in. And yachtsmen cannot sail into a foreign port with firearms aboard, in most places they'll be arrested on the spot by the customs people. Drug paranoia.

Many shipping companies register their substandard , antique ships under foreign flags and hire polyglot foreign crews to avoid paying them decent wages or paying for the maintenance and equipment to pass safety inspections and regulations. Many merchantmen often steam across oceans on autopilot rather than pay sailors overtime to stand helm and lookout watches. Losses of cargo can always be passed off to the insurers. This is an example of a totally unregulated industry. If they don't even have proper fire extinguishers aboard, they're not likely to carry bazookas.