So towards the rear pylon might make sense then? I am also wondering why there is no talk about reinforcements when cutting holes in the boat. I don't think the inspection port has great structural qualities. I was thinking about reinforcing the ring from the inside with fiberglass sheet.

I recently replaced thru hulls on a 23 footer and the seacocks are backed with 1/2" marine plywood blocks. I think marine plywood will ultimately rot inside a cat hull, even if it's sealed. An easier route maybe is to get in inside mounting ring for the port and epoxy it into place. Of course the problem is getting it inside the hull. I was just going to cut it in one spot.