A must have with certain restrictions to the type of activity...

I have always been a fan of crystal case backs. However, the majority of crystal casebacks are dress watches.

I am a big fan of sports watches, but haven't come across many that have a crystal CB. I know of a few that do have it,
AP RO Jumbo, GP Evo3. Not sure if the PP Nautilus Jumbo, ref# 3710 has a hinged back.
If there are more I would love to find out what they are.

I would love to see clear casebacks on the VC Overseas, GP Sea Hawk II, Chopard Pro One, and other watches in this
category.

If you are really into deep diving sports watches, then I would recommend a watch with a solid caseback, and a higher
depth rating. However, for the majority of us who just love the ways it looks and feels, a crystal caseback would be a
very nice touch. I would even be happy if the watch had a hinged back, that opened to a crystal case back. The deepest it would see is probably 75 - 100 feet. IMHO.

Best regards,

Kevin