While steaming at 12 knots, your vessel burns 45 tons of fuel per day. What will be the rate of fuel consumption if you decrease speed to 11.5 knots?

Correct Answer: Option D — 40 tons/day

According to Bowditch rules for marine propulsion, fuel consumption varies approximately with the cube of the speed. Evaluating $45 \times (11.5 / 12.0)^3$ determines the new daily fuel consumption rate to be 40 tons per day.