## 4 Conclusions and Recommendations  
The leaked marine oil ignited by the heated surface of machinery in the fishing vessel's engine room provides deadly risks that significantly change the environmental conditions. This research reveals the effects of temperature, wind velocity, and humidity on the heated-surface ignition characteristics of leaked marine oil in a fishing vessel's engine room. It explores the new correction relationship for predicting the heated-surface ignition probability and ignition occurrence of marine oil with corresponding engine room condition parameters. The noteworthy findings of this study are as follows:  
* Elevated heated-surface temperatures lead to significantly different initial ignition positions of marine oil, and the distance between the ignition height and oil is closely related to heated-surface and environmental factors. Higher initial ignition occurs without mechanical ventilation, and the flame spreads along a path to the remaining oil surface. A lower ignition position occurs under ventilation, forming stable combustion. * The ignition probability of marine oil shows a gradual increasing trend with elevated heated-surface temperatures. The prediction model developed in Equation (14) can be applied to assist in the investigation of fire sources caused by marine oil leakage in a fishing vessel's engine room. * The ignition height of the marine oil on the heated surface presents a downward trend with the increase in heated-surface temperature. This indicates that at the same heated-surface temperature, the enhanced engine room's wind velocity results in a longer ignition delay time for the leaked marine oil. * The engine room's humidity inhibits the upward transfer of heat; however, the degree of inhibition is limited. It is found that the increase in humidity in the fishing vessel's engine room has a significant impact on the ignition delay time of the marine oil on the heated surface. For the scientific prevention and accurate measures of fire accidents in fishing vessel engine rooms, corresponding fire prevention measures should be taken according to the leaked marine fuel types induced by different physical hazards in engine rooms. At present, the ignition source is the energy source in the initial stage of the combustion reaction, and it is necessary to induce a fire accident in a vessel's engine room. Based on our findings, the prevention and elimination of the heated surface is the most critical link to cut off the reaction chain in a fishing vessel fire. This work expands the existing limitations of engine room fire assessment, providing more support for ignition source control in enhance fishing vessel operation safety. Based on the findings of the experimental and numerical works, combined with the research on the initial ignition mechanism and flame propagation characteristics of leaked marine diesel in engine rooms, the following recommendations are proposed:  
* Identify leakage sources of fuel. This requires inspecting marine diesel and lubricant oil piping lines for loose fittings and missing bolts on flanges and non-metallic hoses in areas where the high temperature takes place. The safety supervisor should regularly assess these components to identify potential leakage sources of marine fuel. * Shield potentially heated surfaces. As the materials used to insulate the heated surfaces will degrade in marine operation processes, resulting in them becoming soaked in oil, it is recommended that they are checked consistently. Even if the insulation of the piping system shows to be in good condition, careful checking is essential in finding hidden, smaller heated spots which could trigger an initial ignition if in contact with marine fuel. * Transform the prevention model. As the ventilation conditions in an engine room are enhanced, the ignition position of leaked fuel above a heated surface gradually increases. This means there should be different requirements for the location of fire monitoring sensors.