Captain Yeong-ho had spent forty years listening to the sea. He knew the groan of a stressed hull, the whisper of a changing tide, and the static hiss of a dying radio. But he had never read a manual.

But it was Section 9.4, buried in the troubleshooting appendix, that saved them. A tiny footnote: “If the unit enters continuous reboot mode after firmware update, perform a cold start by shorting pins 5 and 9 on the DB-9 connector for 10 seconds.”

“Section 3.1: ‘Ensure the NMEA 0183 baud rate matches the autopilot. Default is 4800. For heading sensors, use 38400.’” He paused. “I used 9600.”

By Section 4.7 (“Grounding the chassis to prevent RF interference”), Min-jun discovered the shielding on the antenna cable was loose. By Section 6.2 (“Sky view must be unobstructed—metal masts create multipath errors”), he realized he’d mounted the receiver too close to the radar array. Each page was a quiet rebuke of his assumptions.