The TR-50717 ("Paradive, Class B") is Tornek-Rayville’s evolution of the military watch specification MIL-W-50717. After a survey of end users, we identified issues and weak points with the first generation contract watches and re-engineered the design to enhance and extend performance in challenging environments. The monocoque case of the first Class As and Bs minimized the number of water ingress points, but in practice the design was challenging to service and crystals developed stress fractures over time rendering them illegible. The two-piece stem the construction required was another vulnerability, usually revealed when the crown came off in one's hand while hack setting the time.
The Tornek-Rayville Paradive utilizes a proven 3 piece construction. The screw back case enables the watch to use a solid one-piece stem, carries forward the ergonomic curved case back, and improves ease of maintenance. The crystal is press fit into the front of the case and made of a tougher synthetic sapphire material that will not develop the "crazing" the first watches did. A unidirectional 120-click bezel, a safety feature for underwater timing, replaces the bi-directional friction bezel. The bezel is also available with either aluminum or acrylic timing dials.
Other notable changes and improvements include the replacement of fixed bars with reinforced heavy duty 2.50 mm spring bars that meet the ISO standards for dive watches. Each unit is also supplied with a thinner set of 1.80 mm spring bars for standard straps. In place of the specified Pm 147, this watch leverages a proprietary non-radioactive luminous material. The Japanese made NE15C movement delivers a longer power reserve and comparable accuracy to the preceding mil-spec.