The Seiko Prospex LX SNR031J1 is a black-coated titanium Spring Drive diver with a silicone strap, a 72-hour power reserve and a manufacturer-stated 300m saturation-diver rating. Its published dimensions vary by source, and the available evidence establishes specifications—not independent hands-on performance—so this review focuses on what Seiko and its official French retailer say about the watch.
What is the Seiko Prospex LX SNR031J1?
The SNR031J1 is the black edition of the Seiko Prospex LX diver. Seiko groups it with the 5R65 Spring Drive family, while the official French Seiko Boutique listing identifies the full reference as SNR031J1. The watch pairs a black-coated titanium case with a silicone strap.
Seiko describes the LX line’s design as striking “an unusual balance.” That is the manufacturer’s design characterization, rather than an independent assessment of the SNR031’s appearance or finish. Seiko’s 2019 Prospex LX line overview provides the collection context, and Seiko Boutique France’s SNR031J1 listing gives exact-model details.
What movement is in the Seiko SNR031?
The SNR031 uses Seiko’s Spring Drive caliber 5R65. Seiko describes the movement as automatic and also permits manual winding. The model has a date display, a 72-hour power reserve and manufacturer-stated precision of ±1 second per day. Seiko’s LX overview also expresses that precision as ±15 seconds per month.
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- PADI SPECIAL EDITION: Men's Prospex Sea diver featuring a PADI Special Edition design with a stainless-steel case and ceramic bezel display.
- AUTOMATIC MOVEMENT: Seiko 4R36 automatic movement offers manual winding, 24 jewels, day/date display, stop-second function, and approximately 41 hours of power reserve.
- 200M DIVER'S WATER RESISTANCE: Rated to 200 meters / 660 feet for diving, with a screw-down crown and screw case back.
- SAPPHIRE CRYSTAL: Sapphire crystal with magnifier and inner anti-reflective coating provides durable dial protection and improved readability.
- DIVER-READY FEATURES: 45mm stainless-steel case, unidirectional rotating bezel, LumiBrite hands, indexes and bezel, plus a secure three-fold clasp with extender.
Those figures are specifications, not results from an independent timing test of a particular watch. The available sources do not establish measured accuracy during wear.
Is the SNR031 a 300m saturation diver?
Seiko’s 2019 LX overview describes the SNR031 as a 300m saturation diver; the official French listing calls it a 300m professional diver. This is Seiko’s stated water-resistance classification, not an independently verified account of underwater testing. The listing also specifies a screw-down crown and a unidirectional rotating bezel.
Rank #2
- WATER-RESISTANT: these water-resistant men's dive watches are ISO scuba-approved to depths of 200 meters
- AUTOMATIC: these self-winding, automatic men's watches are powered by your movement, with a power reserve of 41 hours
- STAINLESS STEEL: features a durable 43.8mm stainless steel watch case and bracelet.
- LUMIBRITE DISPLAY: this men's automatic watch features a highly-legible display with LumiBrite hands and markers
- 4R35 CALIBER: equipped with the reliable caliber 4R35 automatic movement, this accurate men's watch keeps precise time
How big is the Seiko Prospex LX SNR031?
Published diameter figures differ: the exact-model French Boutique page lists 44.00 mm, while Seiko’s 2019 LX overview gives 44.8 mm for the SNR029/SNR031 family. Seiko’s overview lists thickness as 15.7 mm for that pair. The retailer page does not provide a useful thickness measurement, so the manufacturer’s family figure is the available published value.
The French listing gives a weight of 110 g and a lug width of 22 mm. A lug-width figure alone does not establish compatibility with any particular replacement strap.
Rank #3
- STAINLESS STEEL CASE built to endure with style, making this watch your perfect daily companion
- AUTOMATIC MOVEMENT for seamless precision in every tick of this watch
- SCRATCH-RESISTANT CRYSTAL to maintain a pristine look even with daily wear and tear on your watch
- LUMINESCENT HANDS for effortless readability in low-light conditions, ensuring you never miss a moment with this watch
- WATER RESISTANT DESIGN ensuring your watch is ready for any adventure, rain or shine
What are the SNR031’s case, crystal and strap specifications?
- Case: Titanium with a black anti-scratch coating, described by Seiko as black hard-coated titanium.
- Crystal: Sapphire with anti-reflective treatment, according to the exact-model listing; Seiko’s LX overview also specifies anti-reflective sapphire for the SNR029/SNR031 pair.
- Strap: Silicone.
- Bezel and crown: Unidirectional rotating bezel and screw-down crown, as listed by the French retailer.
These are published product details; they do not establish how the coating, crystal, strap or controls perform in use.
What is the difference between the Seiko SNR031 and SNR029?
The SNR029 is the closest sibling in Seiko’s launch-era LX grouping. The core movement and water-resistance class are shared, while the exterior configuration differs.
Rank #4
- AUTOMATIC MOVEMENT: Seiko 4R35 automatic movement includes manual winding, 23 jewels, date display, stop-second function, and approximately 41 hours of power reserve.
- 200M DIVER'S WATER RESISTANCE: Rated to 200 meters / 660 feet for diving, with a screw-down crown and screw case back.
- STAINLESS-STEEL CASE: 41.7mm stainless-steel case measures 12.3mm thick with a 49.5mm lug-to-lug distance and 20mm lug width.
- HARDLEX CRYSTAL: Durable Hardlex crystal protects the dial, while LumiBrite on the hands, indexes, and bezel improves low-light visibility.
- DIVER-READY DESIGN: Unidirectional rotating bezel and three-fold clasp with secure lock, push-button release, and extender provide practical functionality.
| Specification | SNR031 | SNR029 |
|---|---|---|
| Movement | Spring Drive 5R65 | Spring Drive 5R65 |
| Water-resistance description | 300m saturation diver, per Seiko’s LX overview | 300m saturation diver, per Seiko’s LX overview |
| Case | Black-coated titanium | Titanium |
| Band | Silicone strap | Titanium bracelet |
| Diameter and thickness | 44.8 mm diameter and 15.7 mm thickness in Seiko’s 2019 family overview; the exact-model retailer instead lists 44.00 mm diameter | 44.8 mm diameter and 15.7 mm thickness in Seiko’s 2019 family overview |
The comparison is useful if choosing between a black-coated case on silicone and a light titanium case on a titanium bracelet. Other Prospex LX references are not automatically equivalent alternatives: Seiko’s overview identifies SNR025, SNR027, SNR033 and SNR035 as 5R66 GMT models with differing water-resistance classes and straps.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.How much does the Seiko SNR031 cost?
When accessed on 2026-10-08, Seiko Boutique France displayed a price of €6,700 for the SNR031J1. This is a regional listing snapshot, not a globally applicable price. Seiko’s 2019 LX overview gave an approximate European recommended retail price of €6,100 for the SNR029/SNR031 pair; that is a historical launch-era figure, not a current price quote.
Best Value
- STUNNING BLUE DIAL: this rugged sports watch features a beautiful Manta Ray-patterned blue dial, with Lumibrite dial indicator hands and markers for low light and a magnified day/date calendar
- BLACK BEZEL: this versatile men’s watch features a black ceramic unidirectional bezel with distinctive scalloped edging, for elapsed timing
- AUTOMATIC & MANUAL: SRPF77 automatic watches for men power up with your natural movements, and feature the ability to wind manually, with 41 hours of reserve power
- WATER-RESISTANT: these rugged stainless steel dive watches for men feature a deep blue silicone strap and are both stylish and robust, following ISO standards for scuba, and are water-resistant to 200 meters
- 4R36 CALIBER: equipped with the reliable 4R36 caliber, these precise men’s wrist watches ensure the most accurate timekeeping
Is the Seiko Prospex LX SNR031 worth it?
The case for the SNR031 rests on its specified combination of Spring Drive 5R65, 72-hour reserve, black-coated titanium, silicone strap and Seiko’s 300m saturation-diver classification. Whether that combination justifies its price depends on the buyer’s preference for this case-and-strap configuration and the value placed on Spring Drive. The sources here do not establish comfort, finishing quality in hand, bezel feel, lume performance, or real-world dive performance, so those should not be treated as proven advantages.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
