Eric Ingelman's Bullet Proof Hatches

He started with the original 1975 hatch and replaced the glazing with 1/2" LEXAN.

Since screws tend to crack plastic glazing he framed the LEXAN with 7/8" x 1/8" stainless straps (as per the engineers at G.E.), countersunk to accept the flat head screws used to secure the plastic in place. The real strength in the installation are the stainless bars across the LEXAN exterior. The bar stock is 1 1/4" x 5/16" and is secured by 4 - 3/8" x 3" carriage bolts and fender washers. The protruding bolts provide a place to dog down the hatches to the interior hatch frames via Z-shaped latches and wing nuts. The photo shows the hatch in the off-shore mode. Locally I only use two latches.

When buying LEXAN be sure to specify MR-10 (scratch and U.V. resistant).