You are conducting trials to determine the maneuvering characteristics of your vessel. While making a turn, you take ranges and bearings of an isolated light with the results as shown. Based on this information, what is the advance for a turn of 90°? Illustration D034DG

Correct Answer: Option B — 870 yards

Advance is the distance traveled along the original course axis from the moment the rudder is put over until the heading changes by a specific angular increment. Plotting radar ranges and bearings against the isolated light during a 90-degree turn yields 870 yards.