You have steamed 499 miles at 21 knots and are burning 462 barrels of fuel per day. You must decrease your consumption to 221 barrels per day with 311 miles left in your voyage. What must you reduce your speed (kts) to in order to burn this amount of fuel?

Correct Answer: Option C — 18.4

In accordance with Bowditch, vessel fuel expenditure varies with the cube of the speed. Evaluating the initial rate of 21 knots and 462 barrels against the target 221 barrels for the remaining 311 miles dictates a speed reduction to 18.4 knots.