One-man bridge operation (OMBO)

One-man bridge operation (OMBO) is a bridge designed and equipped so a single qualified officer can keep the navigational watch as sole watchkeeper, including as sole lookout in daylight, with technical redundancy covering the missing second pair of eyes. IACS Unified Requirement N1 sets the construction standard: duplicated and monitored navigation systems, a bridge navigational watch alarm (BNWAS) that escalates to back-up officers if the watchkeeper does not respond, and ergonomic console layout. Class records it as a notation. OMBO does not override STCW A-VIII/2: a dedicated lookout is still required at night and in restricted visibility. Early night-time trials found watchkeeper fatigue and missed alarms, which shaped the BNWAS and redundancy rules.