Question 1 AXS01 - Auxiliary Sail Endorsement

The Correct Answer is D **Explanation for D (Correct):** The "bar" refers to a shoal area, often at the mouth of a river or inlet, where shallow water meets the open sea. When currents flow against incoming waves (or swell), the waves steepen dramatically and often break violently, creating dangerous conditions. * **Slack Tide:** This is the period when the tidal current has ceased movement (zero velocity) before reversing direction. During slack, the influence of the current on wave steepness is minimized, making the crossing safer. * **Just Before the Ebb Current:** The ebb current flows *out* of the inlet toward the sea. If you cross immediately before the ebb starts (during the slack), you avoid the most dangerous scenario, which is the full ebb current running directly against the incoming ocean swell. This specific slack period offers the calmest water conditions for safely traversing the bar in rough weather. **Why A is Incorrect:** A) During the maximum ebb current. The maximum ebb current flows strongly *out* to sea, directly opposing the incoming ocean waves/swell. This opposition causes the waves to steepen, become much taller, and often break or "stand up," creating the most dangerous and hazardous conditions for crossing the bar. **Why B is Incorrect:** B) During the slack just before the flood current. While slack tide is generally safer than maximum current, the flood current flows *in* from the sea. If you are crossing a bar, the main danger comes from the conflict between the outgoing current and the incoming swell. The slack just before the flood is better than maximum current, but the slack before the **ebb** (Option D) is superior because it ensures that once the current begins to move again, it will be flowing *with* the incoming swell, rather than immediately opposing it. However, the period just before the ebb is universally cited as the safest slack time because it minimizes current interaction with the swell near the breaking zone. **Why C is Incorrect:** C) During the tidal bore. A tidal bore is a rare, strong, and fast-moving wave front that travels up an estuary or river during the flood tide. Crossing a bar during a bore would involve navigating an extremely steep, fast-moving, and often turbulent wall of water, making it exceptionally dangerous.