The component compositions of marine fuel oils satisfying the requirements of TU 38.401-58-302-2001 (ISO 8217) with maximum inclusion of gasoils from destructive refining of crude oil were developed. Light gasoils replace standard diesel fuel in marine fuel oil. The demulsifiability of light and heavy catalytic and coker gasoils and vacuum distillates I and II was evaluated. Its dependence on not only the content of adsorbed resins and aromatic hydrocarbons in the components of the fuel but also and to a greater degree on their ratio in the disperse system was demonstrated. The higher this ratio is, the lower the demulsifiability of the fuel.