http://www.thewatchbox.com The IWC Aquatimer Deep Three. It combines the remarkable mechanical depth gauge of the first model with the robust size and modern style of the second; IWC builds on past success by introducing a lightweight titanium case, unique SafeDive unidirectional bezel, and quick-change strap system on the Deep Three. The mechanical depth gauge of the IWC Aquatimer Deep Three reads to 50 meters. IWC limits the reading to this depth based on the watchmaker's conviction that 50 meters is the safe maximum for amateur divers; the watch as a whole is water resistant to a much more imposing 100 meters. Unless your name is Jacques Mayol, you're unlikely to test the limits of this one. IWC openly advertises the Aquatimer Deep Three as an analog backup for modern electronic diving computers. To that end, the company enhances the safety value of the Deep Three with a unidirectional internal bezel that can be used to time intervals of up to 60 minutes when aligned with the watch's minute hand. However, the bezel can only be advanced by securely gripping and turning the external bezel - a separate component. By separating the actuating ring from the bezel itself, IWC reduces the chance of an accidental shortening of a dive, and the internal bezel can be fully treated with luminescent material that would be exposed to degradation on a conventional external bezel. For good measure, the IWC Aquatimer Deep Three employs the quick-release lugs that feature on all of IWC's latest Aquatimer references. With a quick flick of the spring tabs, the comfortable corrugated rubber strap can be swapped for a textile unit or a metal bracelet. An automatic IWC caliber 30120 keeps the beat. Based on the ETA Cal. 2824, this rugged movement is as tough as the Deep Three itself, features a jump date, and sports a stop-seconds (hacking) mechanism for synchronization to a reference time. For once, see a sequel that succeeds; this IWC Aquatimer Deep Three can be viewed in high-resolution images on our website, www.thewatchbox.com. Video and content by Tim Mosso.