Security equipment and systems disallowed for use on board include:

Under international maritime law and the ISPS Code, commercial vessels are generally prohibited from carrying firearms, except in very specific circumstances with explicit authorization from the Flag State and coastal states. Other items like locks, razor wire (with proper precautions), and searchlights are commonly used security enhancements.

Relevant Framework: STCW 2010 Manila Amendments • DG Shipping E-Learning & Exit Exam Standards • Security Training for Seafarers with Designated Security Duties (STSDSD).