That's the old Jaques Cousteau, U.S. Divers design and it is truly bizarre and uncamera-like. How do you like that shutter/wind mechanism? Go out in winter and you never even have to take off your mittens to use it.

I remember when I bought my old used Nikonos II . I filled my sink, held my breath, immersed it, and let out my breath in relief, when saw that there wasn't a stream of bubbles coming from it.