Diving With An Icon Of Nostalgia - The Momentum Sea Quartz 30

Don’t Drink The Quarry Water In Virginia

By Jacob Van Buren

The year is 1980. You’re the son of a naval aviator killed in the Korean War. You were the star quarterback at the United States Naval Academy, served as a Navy SEAL in Vietnam, and recently resigned your commission as a Naval Intelligence Officer. Now, you handle security at the Hawaiian estate of a mysterious thriller author while also working as a private investigator, not to be confused with a “private eye”, thank you very much. What watch would you wear?

If you answered “Chronosport Sea Quartz 30,” you’d be correct. Legions of fans will be screaming that it should be the Rolex GMT-Master reference 16750, a watch just as synonymous with mustachioed star Tom Selleck as his red Ferrari 308 or the actor’s enviable collection of Aloha shirts.

A Chronosport Sea Quartz 30 on Tom Selleck, an icon of 1980s style.

However, long before Selleck was a Rolex man, one of television’s favorite PIs wore a charming and relatively inexpensive quartz dive watch from a brand called Chronosport. The humble Sea Quartz 30 is the watch Selleck wore for the first three seasons of the hit show Magnum, PI. It was also one of the earliest quartz dive watches, released in 1977 by Chronosport, a subsidiary of the St. Moritz Watch Corporation created roughly a decade earlier to market tool watches like the Sea Quartz 30 and the also-awesome analog-digital UDT.

For a former SEAL like Magnum, the no-frills Sea Quartz was a practical companion that could keep up with his active lifestyle. Despite its modest position relative to Rolex, the Chronosport was not a cheap watch. The Sea Quartz was rated for 300 meters of water resistance and powered by a Swiss quartz caliber accurate to “one minute a year.” It retailed for $165 on a Tropic rubber strap and $190 on a stainless steel bracelet in the late 1970s, the equivalent of somewhere around $850 to $980 in today’s dollars. For Lieutenant Magnum’s O3 salary, this was not an insignificant amount. Despite its Selleck connections, Chronosport the brand is long since gone, having met its end sometime in the late 1990s.

But St. Moritz is still around, and the current owners of the family business decided to revive the Sea Quartz under their sporty “Momentum” brand. And did they ever. Studying original cases, dials, and hands, Momentum has replicated the original Sea Quartz down to nearly the last detail. Nearly. As they no longer own the Chronosport name and iconic sailboat logo, the modern Momentum equivalents have been substituted. This will be a deal breaker for some, but taking into consideration the sub-$300 price point, an otherwise faithful recreation of the original design, and an impressive list of specs for the price, I would argue the Momentum version deserves a closer look as well as a chance to once again make a name for itself beneath the surface.

Making preparations to dive with the reissued Sea Quartz 30, it seemed fitting to break out the sort of gear Magnum used in the show. Selleck’s character seemingly retained much of his issued equipment, often wearing a mix of US Navy, US Divers, and Scubapro gear. Shouldering my tank, I looked out over the dive site. Deep in rural Virginia, our quarry was far from Hawaii. Still, the water promised to be warm and I was in good company. Old friends Ben Lowry and Brock Stevens stood ready in the water—I’ll let you determine who is TC and who is Rick in this scenario—along with new friend John Howton.

Clad only in UDT shorts and a U.S. Divers wetsuit jacket, I was going to need as tropical of conditions as I could get. I spat in the Wraparound mask around my neck and rinsed it off in the water, now chest height. Orally inflating my “horse collar” buoyancy control device (BCD) and grabbing my U.S. Divers Calypso’s second stage, we began our swim. I looked down at the Sea Quartz on my left wrist, rotating the bezel to mark our start. The 120-click bezel is slim yet satisfying, ratcheting into position with a high-pitched click that feels well above the watch’s price point while also offering luminescent indices within its sapphire insert, a nod to the Bakelite bezels on the original model.

The Sea Quartz 30 uses the famed “Monnin” case architecture, a popular design seen on dive watch luminaries from the Heuer 844 to CWC’s Royal Navy Diver. It is thin with slightly curved lugs, the top radially brushed with polished sides beginning with chamfers on the lugs, and sweeping crown guards, concealing much of the Sea Quartz’s unsigned crown. Keen-eyed patent aficionados trace the design to Swiss case manufacturer M.R.P., not Monnin, but I digress.

My old jet fins easily propelled me along, keeping up with Brock and Ben’s more modern equivalents from Apeks. I catch Ben in the side panel of my Wraparound mask, neutral in the water as we work our way deeper. Light fades quickly here, lending a deep emerald shade to the water’s hue. The Sea Quartz didn't skip a beat. Its lume is surprisingly good for its price point, lasting through the night and surpassing many watches costing more than triple its price. The bezel’s lume, while not as bright, is adequate for any dive requiring it. All that is required is a quick hit from your torch and it's ready to go.

The Sea Quartz 30 is available on a stainless steel jubilee-style bracelet or a Tropic-style FKM rubber strap, just like the original. The bracelet is solid—almost feeling heftier than the watch itself—with a push-button dual deployant clasp and six positions of micro adjust. Despite the bracelet’s quality, my preference is—as it was for Magnum—the Tropic-style rubber. 42mm in diameter, the case wears comfortably on my 6.5-inch wrist, with the relatively short 47mm lug-to-lug rendering it compact for its size, regardless of whether it’s being worn over a wetsuit or not.

Making the underwater rounds, curious fish wandered by, glancing at our bubbles before ultimately deciding their interests lay elsewhere. I carefully modulated my breaths, using my lungs to maintain buoyancy within the water. I looked down at the Sea Quartz, still ticking away our bottom time. Diving with a watch, at least in my experience, tends to tell you something about it. Some come into their element and transform into hyper-legible bottom timers; some transfer you to another time; and others sometimes change for the worse.

The Sea Quartz, to my bemusement, did not change at all. From a purely functional perspective, this is arguably ideal—it was just as comfortable and legible underwater as it was topside—yet underwater it was missing a certain romance that has come to be associated with its name. No, the watch won’t magically transform you into Tom Selleck, but it will provide you with what may be the best-in-class option for a readily available vintage-inspired dive watch for those seeking a healthy dose of nostalgia for the 1980s.

--

READ MORE FROM THE DIVE LOG: Iconic Dive Watches In Action

Thanks to Jacob Van Buren for writing another great piece for Submersible Wrist. If you’re a fan of vintage diving history, be sure to check out his Instagram page, @sea_vue. Also, thanks to active duty US Navy Diver, Brock Stevens (@deepsea.edc) for the great photography in this article.