Aquadive Time-Depth Electronic Dive WatchAh, the 1970sa time when tool watches meant business. No compromises, no concern for slipping under a cuffjust pure function driven design. This hefty 46mm dive watch is a true engineering marvel, featuring a battery powered movement that winds the mainspring and utilizes a unique diaphragm system to measure and display depth underwater. At 12 oclock, youll find a valve that allows water to enter a metal tube filled with oil inside the casean