Question 70 OSV01 - Master/Chief Mate - Offshore Supply Vessels

The Correct Answer is A **Explanation of Option A (Correct):** Option A, "Slow down when passing moored vessels," is the correct action to reduce wake damage. Wake damage is caused by the large waves created by a moving vessel (its wake). The size and force of a vessel's wake are directly proportional to its speed. When a vessel slows down, the energy transmitted into the water decreases significantly, resulting in much smaller and less damaging waves. This is often mandated by "No Wake" zones near marinas, docks, and moored vessels. **Why Other Options are Incorrect:** * **B) Alternate engine speeds:** Alternating engine speeds does not systematically reduce the wake. If the vessel maintains high average speeds or periodically accelerates, it will still generate large, damaging wakes. * **C) Apply rudder in both port and starboard directions:** Rapidly applying the rudder back and forth (sometimes called "steering a serpentine course") can actually *increase* the turbulence and size of the wake, as the stern of the vessel swings more widely, pushing more water. * **D) Passing close aboard to the moored vessel:** Passing close aboard means passing very near the other vessel. If you pass closely, the energy of your wake hits the moored vessel with greater intensity, increasing the risk of damage (e.g., snapping lines, causing collisions, or damaging docks). To minimize damage, you should pass slowly (A) and as far away as safely possible.