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A free scan shows the junk files, broken settings and background clutter dragging Windows down - then fixes them in one click.Free scan · Windows 10 & 11The Longines HydroConquest L3.784.4.56.9 is a 43 mm automatic dive-style watch with a black ceramic case and matt black ceramic dial. Longines lists a date, up to 72 hours of power reserve and water resistance to 30 bar; its U.S. product page showed a price of $4,700 when accessed in 2026. The available material establishes specifications, not a hands-on wear test, so this guide focuses on what the exact reference offers and what remains unverified.
What is the Longines HydroConquest L3.784.4.56.9?
It is the all-black ceramic, 43 mm automatic version of the HydroConquest. Longines’ U.S. listing identifies the case as black ceramic and the dial as matt black ceramic, with a rubber strap. The 2019 Swatch Group announcement also described an all-black ceramic HydroConquest with a 43 mm case. Longines’ product listing is the source for the current reference specifications; Swatch Group’s 2019 announcement provides historical context.
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Longines describes the broader collection as combining “modern design, Swiss watchmaking expertise and high-performance features.” That is the brand’s collection positioning, rather than an independent assessment of this reference. Longines HydroConquest collection and product page.
Specifications for reference L3.784.4.56.9
| Specification | Longines-listed detail |
|---|---|
| Reference | L3.784.4.56.9 |
| Case diameter | 43 mm |
| Case and dial | Black ceramic case; matt black ceramic dial |
| Movement | Self-winding mechanical; 25,200 vibrations per hour |
| Power reserve | Up to 72 hours |
| Functions | Hours, minutes, seconds and date |
| Bezel and crown | Unidirectional rotating bezel; screw-in crown |
| Water resistance | 30 bar |
| Crystal | Scratch-resistant sapphire with several anti-reflective coating layers on both sides |
| Dial markers | Super-LumiNova |
| Strap and clasp | Rubber strap with double-safety folding clasp and push-piece opening |
| U.S. listed price | $4,700 on Longines’ U.S. page when accessed in 2026; price and availability can change |
These are manufacturer specifications, not independent measurements. Longines’ collection description says HydroConquest models can vary by movement and model, and that collection features include water resistance up to 30 bar, a unidirectional bezel, screw-in crown and screw-down case back. For this particular reference, the product listing specifically confirms 30 bar, the unidirectional bezel and screw-in crown; the reviewed listing material does not establish a screw-down case back for this reference. Longines product and collection page.
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- Automatic L888 movement. hours, minutes, seconds. Screw-down case back
- Stainless steel with double security folding clasp with micro adjustment system
- 5 Year International Warranty
What is known about its movement calibre?
The current Longines product-page material reviewed specifies a self-winding mechanical movement, a rate of 25,200 vibrations per hour and up to 72 hours of reserve, but does not name the calibre. The Swatch Group’s 2019 announcement identifies calibre L888.3 for the all-black ceramic HydroConquest it announced, along with the 43 mm case. Because the current listing excerpt does not repeat the calibre designation, treat L888.3 as the historical announcement’s attribution rather than a separately confirmed current listing detail. Swatch Group, 2019; Longines current U.S. listing.
Price and regional availability
Longines’ U.S. product page listed reference L3.784.4.56.9 at $4,700 when accessed in 2026. This is a dated U.S. listing, not a guaranteed current price or a worldwide price; other markets use different currencies and may show different pricing. Check Longines or an authorized local retailer for current regional price and availability. Longines U.S. product page.
Rank #2
- Automatic L888 Movement, Hours, minutes, seconds, and date. Screw-down case back
- Brown Leather strap with buckle
- 5 Year International Warranty
How it differs from other HydroConquest versions
The clearest confirmed distinctions are the 43 mm diameter, all-black ceramic case and dial, and rubber strap. HydroConquest specifications vary by reference, so do not assume that a figure or feature listed for a different model also applies here.
Longines’ 2026 collection material discusses other variants, including a 42 mm model with calibre L888.5. Those details belong to that variant, not to L3.784.4.56.9. The available material does not provide enough matching technical specifications and prices across other references for a reliable full comparison. Longines 2026 HydroConquest captions.
Rank #3
- Automatic L888 Movement, Hours, minutes, seconds, and date. Screw-down case back
- Brown Leather strap with buckle
- 5 Year International Warranty
When comparing HydroConquest references, check the exact reference number and compare case diameter, material, movement and reserve, strap or bracelet, water resistance, and current local price. Dial and bezel visibility should be assessed for the specific version rather than inferred from a shared collection name.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.What specifications do—and do not—tell you
The official specifications establish materials, functions and stated performance ratings, but they do not document this watch’s fit on a particular wrist, comfort, real-world legibility, measured timekeeping or durability. The cited materials are Longines and Swatch Group product or corporate sources, not an independent inspection or test. A 43 mm case diameter alone also cannot establish how the watch will wear; wrist fit depends on the case’s other dimensions and the wearer, and those details are not established in the material cited here.
Quick Recap
Best Value
- Automatic L movement, hours, minutes, seconds. Screw-down case back
- Stainless steel with double security folding clasp with micro adjustment system
- 5 Year International Warranty
Rank #4
- Premium Material:Equipped with a precise Japanese 8215 movement, this dive watch guarantees accuracy.Sapphire crystal outperforms mineral glass with its superior hardness, scratch resistance, and clarity
- Unique Design:The AD2085 men's automatic watch features large, easy-to-read numbers, a rotating ceramic bezel that's easy to grip and turn, combining practicality with stylish design
- Versatile Function:Water-resistant to 200 M,this waterproof watch is ideal for diving.The luminous feature aids night-time readability,Clearly visible underwater,enhancing its outdoor functionality
- Size:Case diameter:42.6mm;Bezel diameter:40.5mm;Case length:48mm;Case thickness:13.5mm;Lug size:20mm;Watch weight:173g;
- Exquisite Presents for Gentlemen:This wristwatch, a masterpiece of classic design and superb quality, serves as a heartfelt present for fathers, husbands, sons, brothers, boyfriends, friends, and beyond. It's ideal for marking life's precious moments, significant milestones, or just as a simple token of appreciation
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.
