Why won't water drain from console cooler - Cobia 216 cc 2009?

[ALE1980]

The fish boxes will drain with the pump on the switch panel. I looked in the area behind it (in the console stand up head area) and all I saw was the black hose that looks like it should drain into the hull. It would not drain. I checked it with a plunger to see if it was clogged. Very little air running out. The user manual shows that hose connected to a valve - no valve. Any ideas? I am sure it is something simple, but can't seem to figure it out.