Longines HydroConquest Automatic vs Oris Aquis Date Calibre 400
Two divers compared — $1,500–$2,500 vs $2,500–$5,000
Quick Verdict
The Longines HydroConquest Automatic ($1,500–$2,500) offers ETA-Based Automatic with Silicon Balance Spring precision in the tier below the Oris Aquis Date Calibre 400 ($2,500–$5,000). The HydroConquest Automatic measures 41mm and is rated 300m (30 ATM). The Aquis Date Calibre 400 counters with Swiss Made craftsmanship and 300m (30 ATM) water resistance. Both are exceptional divers for their respective tiers.
Transparency — We earn a small commission on purchases made through our Amazon links. This doesn't affect our editorial independence.
Specifications Compared
| Feature | Longines HydroConquest Automatic | Oris Aquis Date Calibre 400 |
|---|---|---|
| Price | $1,500–$2,500 | $2,500–$5,000 |
| Case Size | 41mm | 41.5mm |
| Movement | Automatic L888.5 | Automatic Calibre 400 |
| Caliber Type | ETA-Based Automatic with Silicon Balance Spring | Oris In-House Manufacture |
| Power Reserve | 72 Hours | 120 Hours (5 Days) |
| Water Resistance | 300m (30 ATM) | 300m (30 ATM) |
| Crystal | Sapphire with Anti-Reflective Coating | Sapphire Crystal with Anti-Reflective Coating |
| Case Material | Stainless Steel | Stainless Steel |
| Origin | Swiss Made | Swiss Made |
Category-by-Category Analysis
Design & Aesthetics
Longines's design language vs Oris's approach
The Longines HydroConquest Automatic features a Stainless Steel case at 41mm with Sapphire with Anti-Reflective Coating protection. The Oris Aquis Date Calibre 400 offers Stainless Steel construction at 41.5mm with Sapphire Crystal with Anti-Reflective Coating. Both represent their brand's distinct design philosophy and heritage.
Movement & Performance
Automatic L888.5 vs Automatic Calibre 400
The HydroConquest Automatic runs the Automatic L888.5 (ETA-Based Automatic with Silicon Balance Spring, 72 Hours power reserve) at 25,200 vph (3.5 Hz) frequency. The Aquis Date Calibre 400 uses the Automatic Calibre 400 (Oris In-House Manufacture, 120 Hours (5 Days) reserve) at 28,800 vph (4 Hz). The Aquis Date Calibre 400 offers a longer power reserve.
Wearability & Fit
41mm vs 41.5mm — different wrist presence
At 41mm, the HydroConquest Automatic wears more compactly on smaller wrists compared to the Aquis Date Calibre 400 at 41.5mm. Water resistance differs: 300m (30 ATM) vs 300m (30 ATM).
Value & Cost of Ownership
Longines sits in the lower tier
The Longines HydroConquest Automatic sits at $1,500–$2,500 and the Oris Aquis Date Calibre 400 at $2,500–$5,000. On the specs that outlast any price: the HydroConquest Automatic uses Sapphire with Anti-Reflective Coating with 72 Hours, against Sapphire Crystal with Anti-Reflective Coating and 120 Hours (5 Days) on the Aquis Date Calibre 400. Service intervals are typically 5-7 years for both.
Water Resistance
300m (30 ATM) vs 300m (30 ATM)
The HydroConquest Automatic is rated to 300m (30 ATM) while the Aquis Date Calibre 400 handles 300m (30 ATM). Both offer identical water resistance ratings.
Materials Face-Off
| Component | Longines HydroConquest Automatic | Oris Aquis Date Calibre 400 |
|---|---|---|
| Ceramic Bezel | Zirconium oxide (ZrO₂) with engraved and paint-filled 60-minute dive scale Mohs 8.5 | Oris Caliber 733 |
| Sapphire Crystal | Flat sapphire with anti-reflective coating on the underside Mohs 9 | Domed sapphire with anti-reflective coating on inside |
| Silicon Balance Spring | Si hairspring in the L888.5 caliber — introduced 2020 across the HydroConquest line | Stainless steel 316L (brushed and polished) |
| 316L Stainless Steel | Brushed flanks with polished bevel edges — mixed finishing for visual depth | Unidirectional rotating, scratch-resistant ceramic insert with 60-min dive scale and lume pip |
| Super-LumiNova | Applied to sword-style hands and all hour indices | — |
Cost of Ownership Compared
The Longines HydroConquest Automatic saves you $592 over 5 years of ownership
Who Should Pick Which
Pick the Longines HydroConquest Automatic if…
- Best-in-class 72-hour power reserve at sub-$2,000
- Silicon hairspring antimagnetic protection at an accessible price
- Swiss heritage enthusiasts — Longines' 1832 founding and Olympic/aviation history
- Legitimate 300m dive capability with everyday wearability
- Value seekers — at grey-market pricing the spec-per-dollar is nearly unbeatable
Pick the Oris Aquis Date Calibre 400 if…
- Dive watch enthusiasts — 300m water resistance is proper dive spec
- Those who prioritize scratch resistance — sapphire crystal
- Dive watch collectors who appreciate proper ISO-rated tool watches
- Buyers who prefer a commanding wrist presence — 43mm case
Longines HydroConquest Automatic
- ETA-base movement at this price — excellent but not "in-house" in the purist sense
- 21mm lug width — awkward for aftermarket straps (most are 20mm or 22mm)
- 25,200 vph (3.5 Hz) — seconds hand sweep is less smooth than 28,800 vph competitors
- Not COSC-certified — no chronometer guarantee (unlike Tudor or Omega at similar prices)
Oris Aquis Date Calibre 400
- Sellita base movement at this price — fair value but not in-house prestige (Caliber 400 variants resolve).
- 43.5mm large for smaller wrists (smaller variants available).
- Proprietary endlinks limit strap options.
Our Verdict
Longines
HydroConquest Automatic
Choose the Longines HydroConquest Automatic if you prioritize ETA-Based Automatic with Silicon Balance Spring engineering, Swiss Made craftsmanship, and 300m (30 ATM) water resistance. At $1,500–$2,500, it delivers Automatic L888.5 with 72 Hours power reserve.
Check Price on AmazonOris
Aquis Date Calibre 400
Choose the Oris Aquis Date Calibre 400 if you value Oris In-House Manufacture technology, Swiss Made heritage, and 41.5mm proportions. At $2,500–$5,000, the Automatic Calibre 400 with 120 Hours (5 Days) power reserve makes it a compelling choice.
Check Price on AmazonThe Bottom Line
The Longines HydroConquest Automatic and Oris Aquis Date Calibre 400 represent two distinct approaches to the diver category — the Longines bringing Swiss Made tradition while Oris delivers Swiss Made engineering.
Frequently Asked Questions
More Comparisons
Explore These Watches
How This Page Was Made
Our comparisons are generated from a hand-maintained specification database and reviewed under our editorial standards. We use AI tools to assemble pages from that data. We don’t invent specs: every number traces back to the database, and when we correct an entry, the fix is applied site-wide. As an Amazon Associate, The Horologist earns from qualifying purchases.