USCG Exam PracticeSingle-screw maneuvering and prop walk
As sternway develops on a single-screw vessel, the apparent pivot point moves aft. What handling consequence does this produce?
- A. The stern becomes more responsive to rudder because the discharge current strengthens
- ✓ The bow swings through a greater arc, requiring the coxswain to monitor and control the bow as well as the sternCorrect
- C. Propeller side force diminishes because the pivot point is now closer to the propeller
- D. The rudder becomes more effective because the suction current increases with the aft pivot point
Why B is correct
USCG Boat Crew Seamanship Manual §10-C states that as sternway develops the apparent pivot point moves aft and the bow may swing through a greater arc, so the coxswain must watch the bow as well as the stern and maintain firm helm control to prevent the rudder from swinging hard over.