I have run across a web site that offers free sample orders of vinyl/rubber end caps. These are perfect for protecting your ports. I ordered two sets of samples for my Aquatica A5000 ports. I ordered VC3500-16 for the 19mm Dome port front and VC2375-16 for the rear which also works for the rear standard port.
I like the idea of a pinned thread for Aquatica 5000 users. If I think of a good tip I'll do it. If someone else starts this then title it the same as the A995 tip thread that is pinned in Tips/Techniques.
I am more than willing to provide any exif info on the pics I posted up if anyone thinks it would help them in their pictures. I shoot the 90dx's and used the external wideangle