The Ulysse Nardin Diver NET OPS and Diver X Skeleton OPS are two distinct 44 mm watches, not simply alternate dial treatments. The NET OPS pairs the UN-118 automatic caliber with a date and small seconds; the openworked Diver X Skeleton OPS uses the UN-372 and displays hours, minutes and seconds. The Skeleton OPS has the longer stated power reserve, while the NET OPS carries a sustainability-focused materials story that Ulysse Nardin itself describes.
What is the difference between the Ulysse Nardin Diver NET OPS and Diver X Skeleton OPS?
The clearest distinction is what each watch puts forward: the NET OPS has a conventional, legible dial layout with a date, while the Diver X Skeleton OPS exposes much of its movement through a skeletonized design. Their references and calibers are also different.
| Specification | Diver NET OPS | Diver X Skeleton OPS |
|---|---|---|
| Reference | 1183-170-8A/0A | 3723-170-2C/0A |
| Case diameter | 44 mm | 44 mm |
| Movement | Self-winding UN-118 | Self-winding skeleton UN-372 |
| Display | Central hours and minutes, small seconds, date at 6 o’clock | Hours, minutes and seconds |
| Power reserve | 60 hours, as stated on Ulysse Nardin’s model page | 72 hours, as stated on Ulysse Nardin’s model page |
| Frequency | 4 Hz / 28,800 vph | 3 Hz / 21,600 vph |
| Parts / jewels | 231 parts / 50 jewels | 187 parts / 23 jewels |
| Caliber diameter | 31 mm | 34 mm |
The official product pages describe a Carbonium® unidirectional bezel on both watches. The Diver X Skeleton OPS page also highlights Carbonium® on the barrel cover at 12 o’clock. These model-page details do not establish the water-resistance rating or the complete case and strap composition for either exact reference.
How do their movements and displays compare?
Diver NET OPS: UN-118 with date and small seconds
The NET OPS’s UN-118 is a self-winding caliber with 231 parts, 50 jewels and a 31 mm diameter. Its 4 Hz beat rate equals 28,800 vibrations per hour, and its stated power reserve is 60 hours. The dial keeps the time display familiar, adding small seconds and a date at 6 o’clock. Ulysse Nardin specifies a DIAMonSIL® escapement for this movement.
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Diver X Skeleton OPS: openworked UN-372
The UN-372 is a self-winding skeleton movement with 187 parts, 23 jewels and a 34 mm diameter. It runs at 3 Hz, or 21,600 vibrations per hour, with a stated 72-hour reserve. Its display covers hours, minutes and seconds, without a date. Ulysse Nardin specifies a silicon oscillator with nickel flyweights, plus a silicon escapement wheel, anchor and balance spring.
The higher frequency of the UN-118 and the longer reserve of the UN-372 are specification differences, not evidence by themselves of greater accuracy, reliability or real-world performance. No independent comparative test figures are established here.
What is the NET OPS sustainability story, and what does it establish?
Ulysse Nardin presents the Diver NET as a sustainability-oriented project. The company says disused fishing nets recovered at French ports are recycled by Fil & Fab into Nylo® polyamide granules. It says Nylo® and Carbonium® are used for the side parts and caseback of the Diver 44MM NET. The brand’s From the Sea to the Wrist: Let’s Recycle article explains that materials initiative; its official Diver NET OPS product page says the Diver NET began as a concept in 2020 and was brought to market soon afterward.
Ulysse Nardin describes Carbonium® as made from aircraft-manufacturing offcuts and claims it has 40% less environmental impact than other carbon composites. That figure is the manufacturer’s claim; an independent life-cycle assessment substantiating the comparison is not established here. The materials description for the Diver 44MM NET should not be treated as a component-by-component materials specification for the exact 1183-170-8A/0A OPS reference.
Rank #3
- Ulysse Nardin Diver Chronometer Automatic Black Dial Men's Watch 1183-170-3/92
How do the prices compare?
Ulysse Nardin’s Greece English Diver collection listing shows these regional list prices:
| Reference | Price shown in Greece English collection listing | Collection description shown there |
|---|---|---|
| Diver NET OPS 1183-170-8A/0A | €15,300 | Steel / nylon case; rubber / ceramic strap |
| Diver X Skeleton OPS 3723-170-2C/0A | €31,100 | Carbonium® / black PVD titanium case; rubber / ceramic strap |
These are prices and material descriptions from that regional collection page, not universal prices or guaranteed transaction amounts. Confirm local pricing, stock, and the exact reference’s specifications with Ulysse Nardin or an authorized seller before buying. The official collection listing is Diver Collection.
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- Ulysse Nardin Diver Automatic Black Dial Men's Watch 8163-175-7M/92
Which one should you choose?
- Choose the Diver NET OPS if you prefer a conventional dial with a date and small seconds, the UN-118 specification, or the brand’s recycled-net materials narrative.
- Choose the Diver X Skeleton OPS if an exposed movement is central to the appeal, you want a watch without a date display, or the longer stated reserve matters more to you.
Neither set of specifications establishes how either watch will wear on a particular wrist or how it performs in independent testing. The shared 44 mm diameter is useful for an initial comparison, but it does not tell the full story of fit or thickness.
Quick Recap
Best Value
- Compatible Models: Ulysse Nardin Marine Diver watch and will fit the watch with 26mm/12mm lugs.
- Model Number(s): 1183-126-3/43 - 1133-210-3/E3 - 1183-122-3/40 - 1183-126-3/40 - 1183-126-3/60 - 1183-126-3/61 - 1183-126-3/62 - 1183-126-3/63 - 1185-122-3/41 - 1186-122-3/40 - 1186-122-3/42 - 1186-126-3/43 - 1186-126-3/61 - 1186-126-3/63 - 1503-150-3/60 - 1503-150-3/63 - 1506-150LE-3 - 1506-150LE-3/63-VB - 1532-150-3/43 - 1533-150-3/40 - 1533-150-3/43 - 1183-122-3/42
- Lug Size : 25/11.5mm; Thickness: 5mm/3.5mm; Long Part Length: 90mm ; Short Part Length: 70mm; Inside Opening: 12mm
- Material: Natural Rubber; Durable & Comfortable
- Package Includes: 1 Set (2 Pieces) Soft Rubber Strap
What to verify before buying
- Confirm the reference number on the offer: 1183-170-8A/0A for NET OPS or 3723-170-2C/0A for X Skeleton OPS.
- Ask for the current water-resistance rating and the complete case, bezel, dial and strap specifications for that exact reference; the captured model-page details do not establish those fields.
- Check the local price, availability, warranty terms and authorized service route with the seller. The published Greece listing is regional and may not match your market.
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.
