Marathon 41mm Steel Navigator w Date (SSNAV-D) Nylon DEFSTAN Watch A robust tool watch that represents a fully re-engineered upgrade to Marathon’s original Steel Navigator , developed in partnership with the Kelly Air Force Base in 1986. The Steel Navigator w ith Date boasts enhanced functionality and unmatched accuracy that caters to pilots, parachutists, and adventurers .   With the ETA F06.412 HeavyDrive-PreciDrive Quartz movement, the 41mm Steel Navigator with Date (SSNAV-D) stands out with unmatched precision, featuring accuracy of ± 10s/year. This model also exhibits a date complication - a first for any Steel Navigator since the design’s initial launch in the 1980’s. The SSNAV-D is built from 316L surgical-grade stainless steel with a screw-down crown and synthetic sapphire crystal, making it operational even when submerged to 10ATM (100m/300ft).  Self-contained tritium gas tubes on the hour markers, and minute/hour hands ensuring constant visibility in low-light environments. Tritium tubes are self-illuminating, containing an isotope of hydrogen that won't dull down over time like photoluminescent paint, meaning the watch will remain fully legible at all hours. Protecting the dial of the SSNAV-D is a highly durable sapphire crystal. This allows the watch to withstand extreme changes in air pressure – necessary for the watch’s use by military pilots at altitudes of over 35,000ft – while also providing scratch resistance and pristine clarity. The SSNAV-D is Swiss-made and Canadian-designed for premium quality and craftsmanship. Movement:   ETA F06.412 HeavyDrive-PreciDrive Quartz No of Jewels:   3 Scale Quantity:   2 Scale Range:   1-12 (13-24) Calendar Type:   Date Luminous Features:   Tritium Gas Tubes Crystal Material:   Sapphire Crown Type:   Screw-Down Case Material:   316L Stainless Steel Case Finish:   Parkerized Bezel Type:   Bi-Directional Bezel Scale:   12 Hour Submersibility:   10 ATM Case Diameter:   41mm Case Thickness:   11mm Lug Width:   20mm