The propeller on a vessel has a diameter of 18.8 feet and a pitch of 21.4 feet. What would be the slip if the vessel cruised 378 miles in a 24 hour day (observed distance) at an average RPM of 76?

Correct Answer: Option C — +1.9%

Calculate the theoretical distance (pitch × RPM × 1440 minutes). Determine slip using the formula: Slip = (Theoretical Distance - Observed Distance) / Theoretical Distance. With a pitch of 21.4 feet and 76 RPM, the theoretical distance is 370.9 miles, resulting in a positive slip of 1.9%.