Sea Beach III
1968–1970 · Stainless Steel · Manual Wind
About the Sea Beach III
Made from 1968 through 1970, the Sea Beach III is a clean, sport-leaning stainless steel dress watch powered by Hamilton's caliber 688 manual wind movement. It belongs to the Sea Beach line, a group of water-themed models from Hamilton's late-1960s Swiss-production era. The round case runs 9mm thick, keeping the profile low on the wrist, and the dial pairs a black field with silver tones and embossed silver markers with lume dot indices. A date window at 3 o'clock and a sweep seconds hand round out a no-fuss, practical layout.
The embossed silver markers are worth a close look on any example you find. They sit proud of the dial surface and are prone to separation or losing their finish if the watch has been exposed to moisture over the years, which is common in anything marketed as a beach or sport watch. Hamilton offered this one at $55 with a bracelet or $49.95 on a strap, so it was priced as an everyday wearer, and many of them were worn exactly that way.
From the Catalog
Hamilton listed the Sea Beach III in stainless steel with a date window and luminous hands, available on a bracelet for $55 or on a strap at $49.95, positioning it as an accessible, versatile everyday watch.
Hamilton Catalog Images
1968
1971
What to Look For
| Dial | Look carefully at the embossed silver markers. Check for any that have separated, shifted, or show corrosion underneath. The black dial field should be even with no fading or water staining near the edges or around the date window. |
| Crystal | The crystal sits inside the bezel and helps retain the dial and movement. Check that it's seated properly with no gaps or separation around the perimeter. Deep scratches in an acrylic crystal are fixable, but a cracked crystal needs replacement before wearing. |
| Movement | Dried lubricants in a movement this old build enough friction to cause erratic timekeeping or full stops. Ask when the caliber 688 was last serviced. If the answer is unknown, budget for a service before putting it in regular rotation. |
| Case | Despite the Sea Beach name, treat this watch as not water-resistant. Vintage case gaskets are decades old and should never be trusted. Check the case back for signs of forced opening, which can leave dings or damage the threads. |
| Crown | Pull the crown gently to test winding and setting. The crown can detach from the stem if pulled too aggressively, so check that it moves smoothly through its positions without wobble or excessive play. |
The Movement
The caliber 688 is a Swiss-made Hamilton manual wind movement running 17 jewels. You wind it daily by turning the crown, and it drives a sweep seconds hand rather than a small subseconds dial at 6 o'clock, giving the dial a clean, modern look. It's a straightforward, reliable movement when properly serviced.