Do the F cameras have underwater housing? I didn't know...

Well, I'd go with a Nikonos III. I actually went with a Nikonos III and 35mm f2.5 lens for a trip earlier this summer. I think it cost me $100-$150 from keh.com. I went with the III because it is all mechanical and so I don't have to worry electronics flooding, which does happen sometimes apparently. Keep in mind that the cameras are scale focus.

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