Do I need to use the plug in my cast net box?

The cast net box is designed to pump out any water that enters the boat.  The plug should always be installed in the cast net drain. The floor drain plug should also be plugged to keep water from entering through the transom scupper.  The scupper is not a reliable water stop.  The floor drain and cast net box can be unplugged if the boat is moving forward and water will be sucked out of the boat by the vacuum created at the transom.