Use of Force Continuum

The use-of-force continuum is the graduated scale of escalation a boarding or interdicting force follows against a non-compliant vessel, moving only as far up the scale as the threat requires. The typical steps run from presence and verbal hail, to visual and audible signals (flags, lights, siren), to blocking and shouldering maneuvers, to warning shots across the bow, to disabling fire aimed at the rudder or propulsion, and finally to force against persons in self-defense. Each step must satisfy necessity and proportionality under the operation’s rules of engagement, and lethal force against a fleeing merchant vessel is generally unlawful absent a threat to life.