What is the 'Camanchaca', and how does it affect maritime navigation along the northern and central coasts of Chile?

1. A dense coastal advection and marine stratocumulus fog bank formed over the cold Humboldt Current, moving inland through coastal valleys and severely reducing visibility to near zero
2. A tropical revolving storm with sustained winds over 64 knots
3. A sudden tidal bore that travels up rivers in southern fjords
4. A high-altitude jet stream that only affects commercial aviation