USCG Exam PracticeSingle-screw maneuvering and prop walk
As sternway builds on a single-screw vessel, the apparent pivot point moves aft. What is the practical consequence of this shift for the coxswain?
- A. The discharge screw current is redirected forward, increasing flow past the rudder and improving steering response
- B. Rudder effectiveness increases proportionally because the rudder is now closer to the pivot point
- ✓ The bow may swing through a greater arc, requiring the coxswain to monitor the bow and maintain firm helm controlCorrect
- D. The stern becomes less responsive to propeller side force because the moment arm from the pivot point decreases
Why C is correct
When the pivot point moves aft as sternway develops, the bow swings through a greater arc. The manual specifically states the coxswain must watch the bow as well as the stern and keep firm control of the helm to prevent the rudder from swinging hard over.