We have many customers call about leaking Beckson opening ports.
After 10 or 15 years being compressed by the tight lens, it is common for the gasket to lose its shape. The result is a poor seal that allows water into the interior. The only solution is a replacement gasket.
But there is an important design aspect of the Beckson ports to be aware of. The ports are designed to accept a fly screen installed in a gap provided between the gasket and the plastic frame of the port. In fact it is the gasket that holds the screen in place. But without the thickness of the screen's frame behind it the lens will not compress the gasket adequately and therefore won't seal. The screen must be in place for the lens to seal properly.
Reportedly, Beckson ports are shipped from the manufacturer with both the screen and a small plastic spacer (the equivalent of the screen's frame only) included. In fact, we have seen more ports without the spacer than with. But over time and a perhaps a series of owners, even if they were there when new, the screen or the spacer may have been lost.
One more caution: If you happen to have both the spacer and the screen, never install both at the same time. Because of the additional thickness, you may break the hinges or frame when you tighten the dogs.
We carry replacement screens and gaskets for both of the port sizes used by Catalina, the 5" X 12" and the 4" X 10".