From 1020, 3 March, to 1845, 5 March, your vessel steamed an observed distance of 845.6 miles. The average RPM was 78, and the pitch of the propeller was 20'03". What was the slip?

Correct Answer: Option D — +4%

Calculate the theoretical distance by multiplying RPM, time elapsed, and pitch. Compare this to the observed distance of 845.6 miles. The slip percentage is determined by the difference between theoretical and observed distance divided by theoretical distance. A positive 4% result indicates the vessel is moving slower than the pitch.