That's probably the inlet or discharge hole for the marine head that was typically installed on the Seafari. The hoses went thru the bulkhead at front of stepdown, so those holes are located pretty far forward. You may find that it's above the waterline when you're up on plane! Intake was on starboard side, discharge on port side. The white spot in this pic just below the FL in the registration No. is where I patched the hole on stbd side when I removed marine head and installed a portapottie. It's located below where the inner step intersects the chine.
