While fixing one of the opening ports in the main cabin of my ODay 34, I was surprised to see no core. I took the port out to re-seal it and there was zero core between the inner liner and the outer fiber glass. At first I thought maybe the leak was so bad that core just rotted away, but after looking further, that would be impossible. I guess they didn't put any material in that spot. I have also looked at the fixed port lights and there is core material in there. Just seemed weird.