The port holes will be acrylic windows in a window frame with O-ring seals. The O-ring will be placed on the side facing away from the water such that when the

The port holes will be acrylic windows in a window frame with O-ring seals. The O-ring will be placed on the side facing away from the water such that when the pressure rises on the window, the pressure on the seal rises as well, making it even more water proof. Same idea for the hatch.