🔍 Key Concepts

• Propeller pitch as theoretical advance per revolution (in feet) • How to apply percent slip to reduce the theoretical distance made good • Converting total distance in feet per day to miles per day (decide if the exam expects nautical miles and the proper feet-per-mile value)

💭 Think About

• First, find the theoretical distance the ship would travel in one day with no slip using pitch and total revolutions. What is the formula? • Next, apply the 7% positive slip. Does positive slip mean the vessel travels more or less than the theoretical distance? How do you adjust the distance using 7%? • After adjusting for slip, convert the final distance in feet to miles. Which feet-per-mile value is appropriate for this type of navigation exam problem?

✅ Before You Answer

• Be sure you multiply pitch (ft/rev) by total revs per day before adjusting for slip • Apply slip as a percentage of distance (e.g., multiply by (1 − 0.07) or (1 + 0.07) depending on what positive slip means in this context) • Use a consistent conversion from feet to nautical miles (check whether the exam typically uses 6080 ft per nautical mile).