Mechanical chronograph fans tend to judge a watch first by what is inside it, and the Marathon CSAR WW194014SS-0105 passes that test immediately. This 46mm Chronograph Search and Rescue watch runs on the ETA Valjoux 7750, one of the most respected automatic chronograph movements ever made, housed in a steel case on a stainless steel bracelet with a black dial.

The Valjoux 7750 has earned its reputation through decades of service in tool watches. It is a robust, self-winding, 25-jewel caliber with roughly 48 hours of power reserve, and in the CSAR it drives a full day/date display at 3 o'clock along with chronograph counters. Few movements feel as purposeful in use; the pushers engage with a firm, mechanical action that quartz chronographs simply cannot imitate. Incabloc shock protection helps it cope with the knocks of real-world wear.

What Marathon has added around it is just as compelling for a collector. The case is 316L steel with a screw-down crown and sapphire crystal and is rated to 300 meters, an unusual depth for an automatic chronograph. The dial combines tritium gas tubes on markers and hands with MaraGlo on the subdials, bezel pip and seconds hand. And the oversized 120-click bezel reflects the SAR line's origins in Canadian Government search and rescue requirements.

Inside and Out: WW194014SS-0105

• Marathon CSAR, 46mm Jumbo automatic chronograph
• ETA Valjoux 7750: self-winding, 25 jewels, ~48h reserve
• Black dial with day/date at 3 and a 1/100-minute scale
• Brushed 316L case, about 17.5mm high, 55mm lug-to-lug
• Rated 30 ATM
• Sapphire crystal; guarded screw-down crown
• Tritium tubes and MaraGlo illumination
• Stainless steel bracelet, 22mm width

A proven Swiss chronograph engine, dressed for duty.