Marine engine room fire suppression (Fireboy, Sea-Fire)

Fixed engine-room fire suppression is required by ABYC A-4 for enclosed engine compartments over a certain size and is universal on cruising motoryachts. Two systems dominate: Fireboy-Xintex (formerly Fireboy) and Sea-Fire. Both use a clean agent (typically HFC-227ea, brand name FE-227, or the newer FK-5-1-12 marketed as Novec 1230) that suppresses fire without corrosion, water damage, or asphyxiation risk to crew. HFC-227ea is being phased out in some jurisdictions (high GWP) in favor of Novec 1230. Sizing: manufacturers publish cubic-foot ratings per bottle; measure your engine compartment (length x width x height) and pick a bottle that meets or exceeds the volume. Never undersize, the concentration required to knock down a fire is chemistry-specific and non-negotiable. Installation rules: (1) Discharge nozzle mounted at the top of the engine compartment, aimed centerline. (2) Automatic AND manual release, the temp-triggered automatic discharge is primary, the pull cable at the helm is backup and lets you fire before the fuse melts. (3) Automatic engine shutdown wired to the bottle: when the extinguisher fires, all engines and blowers shut off within 5 seconds. Without engine shutdown, the engines suck the agent out of the compartment before it can knock down the fire. (4) Annual inspection: pressure check (gauge should be in green), hydrostatic test every 12 years, full recharge after any discharge (never partial). (5) After discharge, ventilate before entering the compartment, HFC-227ea and Novec 1230 both displace some oxygen at knockdown concentration.