The propeller of a vessel has a pitch of 19.0 feet. If the vessel traveled 183.5 miles (observed distance) in 24 hours at an average of 44 RPM, what was the slip?

Correct Answer: Option B — +7.4%

Engine distance: (44 * 1440 * 19) / 6076.1 = 198.1 miles. Slip: (198.1 - 183.5) / 198.1 = 0.0737, or +7.4%. Positive slip is the standard result when the vessel's speed through the water is less than the theoretical speed of the propeller, as defined in Bowditch navigation principles.