The propeller on your vessel has a pitch of 18'09". If the observed distance for a day's run was 399.4 miles and the average RPM was 86, which statement is TRUE?

Correct Answer: Option A — The slip is a negative 5%.

Engine distance is calculated by (RPM × 60 × 24 × Pitch) / 6080.2. With a pitch of 18.75 feet and 86 RPM, the engine distance is 381.6 miles. Slip is (Engine Dist - Observed Dist) / Engine Dist. A negative slip indicates the vessel traveled further than the theoretical engine distance.