Sentinel
1940–1946 · 10k Yellow Gold Filled · Manual Wind
About the Sentinel
The Sentinel was produced from 1940 through 1946 and carries one of Hamilton's more practical engineering stories from that era. It runs on the 17-jewel caliber 987S and features a sweep seconds hand paired with a second-setting feature that allowed the wearer to stop the movement precisely at the 12 position, set the time, and restart the watch synchronized to the second. That kind of functionality was genuinely useful for doctors, radio technicians, and engineers who needed exact timekeeping, and Hamilton marketed it directly to those users. The Sentinel shares DNA with the Secometer, another Hamilton model built around precise seconds measurement.
Finding a Sentinel in honest condition means paying close attention to the dial, which came in more than one configuration. The standard silver dial with luminous painted Arabic numerals is the most common, but examples also surface with enamel dials and Roman numerals, as well as dials with applied gold numerals, and those variants are meaningfully different from each other in character and collectibility. The 10K yellow Gold Filled case holds up reasonably well over time, but the sector-style dial layout and swept lugs give this watch a look that feels more purposeful than decorative, which is part of what makes it interesting.
From the Catalog
Hamilton introduced the Sentinel at $42.50 in 1940, or $46.75 including federal tax, and positioned it squarely as a precision tool for professionals who needed to set their watch right to the second. The catalog copy called it out specifically for doctors, radio technicians, and laboratory engineers, which was not boilerplate at the time but a genuine description of who Hamilton expected to buy it.
Hamilton Catalog Images
1940
1941
What to Look For
| Dial | Confirm which dial variant you have before buying. The standard silver dial with luminous painted Arabic numerals, the enamel Roman numeral version, and the applied gold numeral dial are all legitimately different watches in terms of look and value. Check for crazing on enamel examples and loss of lume material on the painted numeral dials. |
| Crystal | The original crystal will be acrylic or glass depending on when it was last serviced or repaired. Check for deep scratches or crazing around the edges, which can indicate an ill-fitting replacement. |
| Movement | Dried oil is a real concern on any Sentinel that has sat unworn for decades. The friction it creates is enough to stop the movement entirely, so if a watch is running inconsistently or stopping under the slightest positional change, assume it needs a full service before anything else is diagnosed. |
| Case | The 10K yellow gold-filled case can show brassing at the lugs and case edges with heavy wear. Check the caseback carefully. These backs can be tricky to open and are sometimes damaged by improper tools, leaving marks or distortion around the edge. |
| Crown | The second-setting feature depends on the crown and stem assembly working correctly. Pull the crown gently and confirm it stops the sweep hand cleanly at the 12 position. If it does not stop or restarts sluggishly, the setting mechanism may need attention. |
The Movement
The caliber 987S is a 17-jewel manual wind movement that Hamilton produced for a range of dress and sport watches during this period. What sets it apart in the Sentinel is the hack-style second-setting mechanism, which stops the movement when the crown is pulled so the wearer can synchronize precisely. It is a compact, reliable caliber that responds well to a proper service but will lose accuracy quickly if oil has dried out from years of sitting.