Photo: Tempus Shop
Catalogue / Longines / ref. L3.788.4.90.6
Longines HydroConquest - L3.788.4.90.6
The Longines HydroConquest is an automatic watch, 42 mm across, with a sapphire crystal, water-resistant to 300 m. It was listed at €2,300 at Tempus at our check on 12 November 2026.
Where to buyChecked 12 November 2026
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Who it suits
Anyone who swims, dives or wants a watch that never needs babying.
Strengths
Automatic movement · Sapphire crystal · Water-resistant to 300 m
Limits
No limit found on the spec sheet.
Our view
A good choice at this price
Of 248 automatic watches within 20% of its price, none is better equipped (crystal, water resistance, titanium).
Depending on what you want
- If your wrist is slim, the Auricoste La Royale measures only 37 mm, at €2,350.
- If you want to spend less without losing anything on the spec sheet, the Alpina Seastrong Diver 300 Heritage Automatic AL-525S4H6 costs €1,795.
- If you like the model but not this version, see the Longines HydroConquest 39mm Bleu Givré, at €2,300.
Reading the spec sheet
What the spec sheet says
- Automatic movement. It winds itself on the wrist, with no battery.
- Sapphire crystal. The most scratch-resistant option.
- Water-resistant to 300 m. Swimming and diving without a second thought.
- Priced below the brand median. It costs 16% less than the median of the 383 automatic Longines watches in the catalogue (€2,750).
Analysis based on the retailer’s spec sheet, without handling the watch.
- Brand
- Longines
- Gender
- Men
- Case material
- Steel, ceramic bezel
- Strap material
- Steel
- Diameter
- 42 mm
- Crystal
- Sapphire crystal
- Movement
- Automatic
- Water resistance
- 300 m (30 bar)
- Clasp
- Double-safety folding clasp with micro-adjustment
- Reference
- L3.788.4.90.6
At this price
Alternatives from other brands
Same type of movement, within 20% of the price.
Questions
The short answers
Is the Longines HydroConquest an automatic watch?
Yes. Its movement is automatic: it winds itself with the motion of the wrist.
Can you swim with the Longines HydroConquest?
Yes. It is water-resistant to 300 m, which covers swimming and diving.
Does the crystal of the Longines HydroConquest scratch?
It has a sapphire crystal, the most scratch-resistant kind.
What size is the Longines HydroConquest?
Its case measures 42 mm in diameter.
How much does the Longines HydroConquest cost?
It was listed at €2,300 at Tempus at our check on 12 November 2026.
Where it ranks
This watch appears in
- Automatic watches with sapphire crystal, water-resistant to 100 m, under €3,000335 references
- Automatic dive watches under €3,000144 references
- Automatic watches, water-resistant to 100 m, under €3,000359 references
- Watches with sapphire crystal, water-resistant to 100 m, under €3,000456 references
- Automatic watches with sapphire crystal under €3,000666 references
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