In Dangerous Waters, where do new POI go when their space is occupied, and what do the yellow or red arrows mean?

Question

Accepted Answer

A POI that would land on fire, smoke, a firefighter or another POI follows the arrows to the next valid space. The arrow colours carry no rule beyond that; red arrows only mark equipment locations.

Flash Point: Fire Rescue

In Dangerous Waters, where do new POI go when their space is occupied, and what do the yellow or red arrows mean?