The Marine Accident Investigation Branch (MAIB) has published its report on the September 2021 fire aboard the Finland-registered ro-ro cargo vessel Finnmaster, which broke out during departure from Hull, England. The blaze, traced to a leaking flexible fuel hose installed during an unapproved modification, caused significant damage to the auxiliary engine room and left the vessel temporarily powerless. The investigation found that the hose did not meet required standards, was poorly positioned, and lacked classification society oversight. Emergency response was hampered by failures in the generator and CO2 fire-extinguishing system, as well as procedural lapses by the crew. The MAIB issued 12 recommendations targeting improved oversight, emergency system testing, and crew training to prevent similar incidents in the future.