USCG Marine Safety Alert

Despite being aware of nearby crankcase and LNG purge vents in their work area, the crew did not know that the vessel was actively using methane as a fuel source. As a result, the work was being conducted in a hazardous zone (see Figure 1). Although marked as a hazardous zone on the vessel’s plans, the zones were not physically or otherwise marked as hazardous on the deck, providing no visual indication to the crew of the potential hazards present.

https://www.dco.uscg.mil/Portals/9/DCO%20Documents/5p/CG-5PC/INV/Alerts/USCGSA_0425.pdf