Craig,

The little brass inspection ports allow access to the space between the hull and liner, which extends into the keel.  Regarding my situation, several gallons of water leaked into the keel before I saw it penetrating through a crack in the liner.  Through my new ports I can check for more water accumulating(hopefully none) and vacuum out any water in the fall and add antifreeze to prevent damage from expanding ice in the keel.  During daily use these ports will be closed so spray, rainwater, beer, etc. doesn't get below the floor.

Martin