You are turning 100 RPM, with a propeller pitch of 25 feet, and an estimated slip of -5%. What is the speed of advance?

Correct Answer: Option C — 25.9 knots

Speed of advance is determined by the product of RPM, pitch, and the slip factor. With 100 RPM and 25-foot pitch, the theoretical speed is 24.66 knots. Applying -5% slip (1.05) accounts for the increased efficiency, resulting in a speed of advance of 25.9 knots.