Aqua Marine
1974–1976 · Stainless
About the Aqua Marine
Made from 1974 through 1976, the Aqua Marine is a stainless steel sport watch built around Hamilton's caliber 825, featuring a day-date complication and a diver's bezel on a round case. It was part of Hamilton's late-era American-branded lineup, a period when the company was producing Swiss-made movements under the Hamilton name following its acquisition by SSIH. The black dial and diver's bezel give it a functional, tool-watch character that sets it apart from the dress watches Hamilton had long been known for.
Finding one in honest condition takes some patience. The black dials on these can show fading or spotting, and the diver's bezel insert is worth a close look since replacements are not easy to source and a damaged one changes the whole feel of the watch. The day-date quick-change mechanism has a reputation for developing quirks over time, so confirming that both the day and date advance cleanly is worth doing before any purchase.
From the Catalog
Hamilton marketed the Aqua Marine with straightforward utility in mind, describing it as a stainless steel selfwind with a diver's bezel and day-date black dial. It retailed for $160 in 1975.
Hamilton Catalog Images
1975
1976
What to Look For
| Dial | Check the black dial carefully for fading, spotting, or moisture damage. The applied indices are small and can loosen or show corrosion at the base. Confirm the day and date displays are legible and that the date window aperture hasn't been disturbed by a clumsy service. |
| Crystal | Look for deep scratches or crazing. A correct replacement crystal should fit flush with the bezel edge. If it's sitting proud or there's a gap, it may be the wrong part. |
| Movement | Ask about service history. The quick-change day-date mechanism in the caliber 825 can develop a specific failure where the wheel for the quick-change separates from the screw that holds it in place, disabling the complication. Confirm both day and date advance correctly at the crown before committing. |
| Case | The case back on these can be stubborn to open and is sometimes marred by previous attempts with the wrong tools. Look around the case back edge for slippage marks. The hidden lugs are a nice design detail but worth inspecting for cracks, especially at the points where the bracelet or strap attaches. |
| Crown | The crown should screw or seat down correctly and operate without looseness in the stem. Also worth noting: even though this watch was sold as water resistant, decades-old gaskets should not be trusted for any water exposure without a full service and pressure test. |
The Movement
The caliber 825 is a Swiss-made automatic movement with a quick-change day-date complication, built during the period when Hamilton movements were being produced by its parent company SSIH. It winds via a rotor and offers a practical feature set for an everyday sport watch. The quick-change mechanism is useful but does have a known vulnerability with the indexing wheel over time, something a competent watchmaker can address during a routine service.