Seabeach
1958–1959 · 10K yellow RGP/SS · Manual Wind
About the Seabeach
Made from 1958 through 1959, the Seabeach is a circle-cased manual wind built on Hamilton's caliber 671 and marketed with a waterproof rating at a time when that designation carried real weight with buyers. The case pairs a 10K yellow rolled gold plate body with a stainless steel back, and the embossed, luminous dial with sweep seconds gave it a sporty, tool-watch character that fit its beach-ready name. It sits in the broader category of Hamilton's mid-century water-resistant dress-sport crossovers, sharing DNA with other waterproof-rated models from the same era.
Surviving examples tend to surface in varied condition, and the embossed dial is worth close attention since the raised numerals and markers can trap moisture or cleaning residue over decades, leaving staining that is easy to overlook until you have the watch in hand under good light. The bracelet configuration originally retailed for ten dollars more than the strap version, and finding one that still has its period bracelet intact is genuinely uncommon.
From the Catalog
Hamilton listed the Seabeach in 1959 as a waterproof, shock-resistant model with an embossed luminous dial and sweep seconds, available on bracelet for $69.50 or on strap for $59.50. The waterproof designation was a genuine selling point at the time, positioned as real utility rather than just a marketing note.
Hamilton Catalog Images
1959
What to Look For
| Dial | The embossed silver numerals and markers at 3, 6, 9, and 12 should be crisp and free of corrosion. Raised elements like these can collect moisture damage that reads as dark staining or pitting at the base of each marker. Look carefully at the lume plots and numerals under a loupe, and check that the white dial surface has not lifted or bubbled near any of the embossed details. |
| Crystal | The Seabeach uses a crystal designed to accept a reflector ring, which is a detail that catches people off guard. Confirm the correct crystal is fitted and that the reflector ring is present and seated properly. A generic replacement crystal that omits the ring will look visually off and affect the finished look of the dial. |
| Movement | Wind the watch fully and confirm it runs smoothly through the mainspring's power reserve. On a movement this age, lubricants dry out and thicken over decades, and that friction alone can stop a caliber 671 or cause it to run erratically. A watch that starts strong and fades within a few hours likely needs a full service. |
| Case | The stainless steel caseback can be tricky to open, and on examples that have been forced or pried incorrectly, the threads or sealing surface may be damaged. Check the back for tool marks around the edge. On the case body itself, the 10K yellow rolled gold plate should show honest wear rather than deep gouges or polishing that has softened the original lines. |
| Crown | Pull the crown gently to the time-setting position and confirm the stem stays put. The set lever screw on the caliber 671 is known to work loose over time, which allows the stem to pull free unexpectedly during normal use. If the stem releases with minimal resistance or feels loose in the winding position, that screw is the first thing to check. |
The Movement
The caliber 671 is a 17-jewel manual wind movement from Hamilton's American production era, reliable and straightforward in its layout. It beats at a traditional rate and uses a sweep seconds configuration, meaning the seconds hand runs from the center of the dial rather than from a subseconds dial. Like most manual wind movements of its generation, it rewards regular servicing and runs best when it has not been sitting dry for years.