By Wesley Wright
A brand steeped in history
The Sea Quartz 30 is Momentum’s return to their heritage catalogue, reviving a beloved model that retains its classic styling while offering modern features. Originally known as the Chronosport Sea Quartz 30 which could be found in dive shops across the country as the value choice for divers and adventurers alike, the watch gained so much popularity that it was picked up by the one and only style legend Tom Selleck in his portrayal of Magnum PI. For the first three seasons Magnum rocks the Chronosport on a rubber strap alongside his signature Paradise Found Hawaiian shirt and Ferrari 308 GTS. For this review, I have asked for the most faithful version of that original watch.

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Key Features of the Momentum Seaquartz 30
Dial: Legibility is king
The dial of the Sea Quartz 30 stays faithful to the original, with a matte black finish and very easy to read green lumed numerals. The typeface of the numerals is virtually identical to the original model, with the added benefit of modern materials through their use of Super-LumiNova on the indices and hands. The hour markers are very visually appealing and classic looking, with a large 12, 6, and 9 being very pronounced, and the tapered baton hour markers being a good size as well.
I am a sucker for 3D markers and indices, and they really hit the mark here with a heavy application of the Super-Luminova which lifts them off the dial providing a very intriguing depth. This dial is clean, which I think adds to its classic charm. I am also a big fan of the choice for the handset. The orange minute hand fits perfectly with the theme of the watch, and the white hour and second hand help complement it with a truly utilitarian look. This dial echoes the feeling of its original model, with the execution and upgrades one would expect in a contemporary dive watch.

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Case
The case for this model is in the same formula we are all used to with dive watches, with great execution on small details and proportions. It pulls its design and dimensions directly from the original model, which had its cases made by MRP. At 42mm across and 47mm lug-to-lug it fits very well on wrist, even for me, a self-proclaimed member of the small wrist society. It lays relatively flat and is very thin thanks to its quartz movement, making it reminiscent of how vintage dive watches feel on wrist. The finishing on the case is also very well executed, with a brushed top, polished transitions and polished sides. The crown guard helps with its vintage feel and lends to its utilitarian nature, protecting the screw-down crown which gives this watch a 300m water resistance.

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Now, on to a very cool part of this case, the bezel. The glass insert bezel has been making a comeback recently, and the Sea Quartz does it very well. The minute track and indices match the colours from the dial, creating a seamless transition between the two. Having all that sit behind glass lets the bezel catch light in ways that gives it more character and depth. One small note about the bezel though, out of the box it can be quite stiff. I had to really give it some effort to get it moving, and it has stayed somewhat stiff in its movement since. With continuous use (let’s be honest, fidgeting) I am sure it will loosen up and glide with ease.

Movement
When talking with Simon at Momentum about which model to snag for a review, we landed on the original Quartz model as it is closest to the Magnum watch. This model is powered by the Swiss-made Ronda R507, which provides quartz accuracy and the ability to slim down the case significantly. If you are looking for the most historically accurate Magnum PI version of this watch, this model is the one to go for. Momentum also offers this model in an automatic version powered by a Miyota 9015, and a solar powered option that uses an Epson VS43A letting the battery charge with sunlight. While I am not the biggest quartz fan, I think it really adds to the appeal of this watch, and gives it a vintage charm to watch the seconds tick away.

Strap and Options
Momentum Watch Corp is also a carrier of a good amount of straps. Since the watches are assembled right here in Vancouver, you can get your watch on one of the many strap options they offer. I went for the original black Ocean-Flex rubber straps, which is a tropic-style rubber. I was surprised to hear this was made from FKM rubber, as I am very used to FKM being stiff and rigid but this is quite soft and supple right out the gate–not to mention comfortable. The Sea Quartz is available on this black rubber strap, an orange rubber strap (yes, it does match the minute hand almost one for one), their black natural hyper rubber strap which features that classic wave pattern from vintage divers, and a stainless steel bracelet. Having felt all these in person, there is no going wrong.
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Specs
| Case | 316L Stainless Steel 42mm Diameter 47mm Lug to Lug 11.3mm Thick 20mm Lug Width Screw Down Crown & Case Back 300m Water Resistance |
| Dial & Crystal | Flat Sapphire Crystal Matte Black Dial Printed Markers Mixed Plongeur Style Handset Super-LumiNova |
| Movement | Swiss Quartz Ronda R507 |
| Strap | Ocean-Flex Rubber Strap (Black & Orange) or Stainless Steel Bracelet or Black Hyper Rubber Strap |
Momentum Seaquartz 30
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Final thoughts
The Sea Quartz 30 cements itself as the legacy model in Momentum’s line up, with timeless style and an awesome backstory. It stands out in an industry filled with brands making “vintage style” watches with Faux-tina and jumping on the trend. It does this by offering their original design and providing its classic charm, while giving it modern upgrades. This to me gives it the understated cool factor it really deserves. If you’re in the Vancouver area, I highly recommend coming to their headquarters and checking out a model yourself. These watches should be appreciated in person.

Pricing & Availability
The Sea Quartz 30 is available for $350 CAD both online and through their headquarters located here in Vancouver.
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About the Author
Based in Vancouver, BC, Wesley shares his passion for watches, photography, and EDC through his Instagram, @wesandwatches. With a strong interest for innovation within horology, he dives deep into brands with compelling stories, thoughtful design, and standout personalities. Beyond watches, Wesley keeps a close eye on men’s fashion and is an avid automotive enthusiast.
Off The Cuff articles are full-length, hands-on reviews of the watch in question and represent the opinion of the author only. All photos are original, unless specified otherwise. If you would like to have your watch reviewed on this site, contact us here.
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Having now seen this in person once and reading through this review, I am feeling one of these coming into my collection soon!
Congrats, in advance.
So glad to hear! After having one in hand, I have to agree!
Brings back my childhood
My dad used to let my brother and I stay up late on Thursdays just to watch it back in the early eighties, lol.