As Chief Engineer of a slow speed diesel propelled vessel operating with constant slip, when considering the effect on the fuel consumption in barrels per mile of a planned increase in operating RPM you utilize which of the following?

Correct Answer: Option C — fuel consumption varies as the cube of the shaft RPM

Marine propulsion power requirements and fuel consumption vary approximately as the cube of the shaft RPM under constant slip conditions, governed by propeller laws. Consequently, even small increases in operating speed result in disproportionately massive surges in total fuel oil consumption.