Hamilton Khaki Field Mechanical Power ReservevsMarathon Steel Navigator SSNAV-D Auto

The Hamilton Khaki Field Mechanical Power Reserve is noted for its 40mm sandblasted case, filling a size gap in the Khaki Field line. It features a new H-23 hand-wound movement with an 80-hour power reserve and a functional power reserve indicator at 9 o'clock. The case is 11.95mm thick, which is described as noticeably thicker than other Khaki Field models, and its proportions differ from classic manual-wind versions. The movement includes a slipping spring to resynchronize the power reserve indicator after shocks. Overall, reviewers appreciate the addition of the power reserve complication to the hand-wound model, though one reviewer noted a preference for a contrasting color on the indicator.

The Marathon Steel Navigator SSNAV-D Auto is praised for its durable construction, featuring a sandblasted steel case with improved lugs, a bi-directional bezel with excellent action, and 100m water resistance. Owners appreciate the constant visibility provided by self-illuminating tritium gas tubes and the precision of its ETA F06.412 quartz movement, which offers accuracy to about 10 seconds per year. The watch includes a GMT bezel for dual timekeeping and a synthetic sapphire crystal. Overall, owners and reviewers rate the Marathon Steel Navigator SSNAV-D Auto highly for its robust tool-watch design and reliable tritium illumination.