Escalation Protocols for Autonomous Naval Vessels: A Legal-Technical Framework for Safe and Credible Maritime Autonomy

Abstract

Autonomous and remotely supervised surface vessels are moving from pilots to operational deployment across defense and commercial shipping. U.S. Navy unmanned surface vessels (USVs)—including mine countermeasures platforms—and commercial Maritime Autonomous Surface Ships (MASS) operate in congested waterways alongside human mariners yet remain governed by legal regimes built around human signaling and post-incident accountability.12 This paper argues that maritime autonomy faces a governance vulnerability: systems may navigate safely but remain legally brittle if their conduct cannot be rendered intelligible under the standards used to assign responsibility after incidents. Maritime compliance is evaluated through reconstruction. The COLREGs apply to “all vessels,” require standardized lights and sound signals, and permit supplemental warnings under Rule 36 only if they cannot be mistaken for authorized signals.3 UNCLOS reinforces compliance as sovereign responsibility by requiring flag states to ensure conformity with generally accepted international safety regulations.4 These rules create an evidentiary burden autonomy often cannot meet. Collision doctrine underscores the stakes: statutory navigation violations can trigger presumptions of fault that must be rebutted by proof.5 In coercive or ambiguous encounters, the burden intensifies because escalation governance depends on demonstrable sequencing and restraint rather than after-action narrative.6 Existing maritime systems generate abundant data but rarely preserve a unified, time-synchronized record of what an autonomous vessel perceived, what it signaled, how it maneuvered, and whether human-on-the-loop judgment boundaries were maintained.7 The paper proposes a maritime assurance operating layer as the enabling infrastructure for lawful autonomy at scale. Non-controlling and platform-agnostic, it does not steer the vessel or execute coercive actions; it fuses heterogeneous sensor streams and operational logs into an audit-grade timeline that captures signaling and escalation sequencing, including Rule 36 warnings and human intervention pathways. By making compliance reconstructable and restraint provable, assurance infrastructure reduces legal exposure, narrows narrative ambiguity in contested waters, and supports coalition and commercial adoption through portable accountability outputs. The core conclusion is that maritime autonomy will scale only if it becomes legible: evidence-grade assurance is a condition of credible, stabilizing autonomy at sea.