Collectors
- Longines HydroConquest 41mm Automatic, Sunray Blue, Rubber Strap (the dive watch) · See price on Amazon
- Longines Conquest 38mm Automatic, Sunray Blue, Rubber Strap (the everyday automatic) · See price on Amazon
Full reasoning, verified listing details, and a comparison table below.
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How We Compared
Both watches come from the same storefront pool and the same seller line: our storefront searches are our searches, not a census, and every listing we opened read "Ships from and sold by Amazon.com," which is Amazon as seller of record rather than a marketplace reseller. We chose the two listings that make the cleanest pair: the HydroConquest 41mm on its blue rubber strap and the Conquest 38mm on its blue rubber strap, both with the L888 calibre, both showing free returns. The Conquest listing is a variant parent with a 38mm and a 41mm size selector; we captured the 38mm child page and make no claims about the 41mm sibling.
For the wider field, our HydroConquest roundup covers the bracelet models and the GMT, the best Longines watches guide places both collections against the Conquest Classic, and watch movement types explains what an automatic calibre is doing behind that exhibition back.
The Dive Watch: Longines HydroConquest 41mm Automatic, Sunray Blue, Rubber Strap
Longines HydroConquest 41mm Automatic, Sunray Blue, Rubber Strap
Longines
- Swiss automatic L888 movement with hours, minutes, seconds and date; screw-down case back
- 41mm stainless steel case, 11.9mm thick; sapphire crystal
- Ceramic unidirectional bezel; sunray blue dial
- Water resistant to 300 metres (30 bar); screw-down crown per the description
- Blue rubber strap, 21mm, with double safety folding clasp and push-piece opening mechanism
- Five-year international warranty stated; model L37814969; Imported
- Ships from and sold by Amazon.com
Why we picked it: Everything about this listing is built around the water. The description states 300 metres, a unidirectional rotating bezel, and a screw-down crown and case back; the spec table records the bezel as ceramic and unidirectional and the case as 41mm and 11.9mm thick, the same case as the black bracelet model in our roundup. The rubber strap closes with a double safety folding clasp with a push-piece opening mechanism, and the description states a five-year international warranty. It is the HydroConquest for someone who will actually get it wet, and the rubber makes it the more casual of the two on the wrist.
The Everyday Automatic: Longines Conquest 38mm Automatic, Sunray Blue, Rubber Strap
Longines Conquest 38mm Automatic, Sunray Blue, Rubber Strap
Longines
- Swiss automatic L888 movement with hours, minutes, seconds and date
- 38mm stainless steel case, 10.9mm thick; sapphire crystal
- Screw-down, transparent sapphire crystal case back (exhibition back)
- Stainless steel fixed bezel (spec table: stationary); sunray blue dial
- Water resistant to 100 metres
- Blue rubber strap, 19mm, with double security folding clasp and micro-adjustment system
- Five-year international warranty stated; model L37204929; 38mm and 41mm sizes listed on the parent page
- Ships from and sold by Amazon.com
Why we picked it: The Conquest is the same calibre in a smaller, slimmer, more dressed-down case: 38mm and 10.9mm thick against the HydroConquest's 41mm and 11.9mm, with a fixed steel bezel instead of a rotating ceramic one. The listing's distinguishing feature is the transparent sapphire case back — screw-down, so it does not cost you water resistance within the watch's 100-metre rating — which lets you see the L888 working. The strap is the more refined of the two: 19mm blue rubber with a double security folding clasp and a micro-adjustment system, which the HydroConquest's clasp does not list. The description also carries a brand history — that the Conquest name was the first Longines collection protected by the Swiss Federal Intellectual Property Office, in 1954 — which we quote as the listing's own claim. This is the watch for a smaller wrist, a shirt cuff, and a wearer who wants to see the movement more than they want a dive bezel.
Comparison Table
| HydroConquest 41mm | Conquest 38mm | Link | |
|---|---|---|---|
| Movement | L888 Swiss automatic, date | L888 Swiss automatic, date | See price |
| Case | 41mm stainless steel, 11.9mm thick | 38mm stainless steel, 10.9mm thick | See price |
| Case back | Screw-down (not described as transparent) | Screw-down, transparent sapphire (exhibition) | |
| Bezel | Ceramic, unidirectional rotating | Stainless steel, fixed (stationary) | |
| Water resistance | 300 metres (30 bar) | 100 metres | |
| Crown | Screw-down (per description) | Not stated | |
| Strap and clasp | 21mm blue rubber; double safety folding clasp, push-piece opening | 19mm blue rubber; double security folding clasp, micro-adjustment | |
| Dial | Sunray blue | Sunray blue | |
| Warranty line | Five-year international (description) | Five-year international (description) | |
| Sizes on the listing | 41mm (this listing) | 38mm captured; 41mm sibling on the parent page | |
| Seller of record | Amazon.com (first-party) | Amazon.com (first-party) |
How to Decide
300 metres or 100 metres: the number that decides most buyers Both listings publish a water-resistance figure and they are not close. The HydroConquest states 300 metres, backed by a screw-down crown and case back and a unidirectional bezel — the construction of a dive watch. The Conquest states 100 metres and a screw-down transparent case back, and its listing does not mention a screw-down crown at all, so we do not assume one. In practice 100 metres covers swimming and showers for most people; the difference is not whether you can get the watch wet but whether the watch is designed around being wet. If diving, snorkelling, or simply the security of a rotating bezel matters to you, the number settles it.
Exhibition back vs rotating bezel: which feature you will actually use The Conquest listing's transparent sapphire case back is the more collector-pleasing feature; the HydroConquest's ceramic rotating bezel is the more useful one. An exhibition back shows you the L888 calibre every time you take the watch off, and on a first Swiss automatic that is a genuine pleasure. A unidirectional bezel times anything — a parking meter, a steak, an air supply — and ceramic is generally more scratch-resistant than steel and does not fade. Neither watch gives you both. Decide which one you would miss.
38mm vs 41mm, and the millimetre of thickness between them The Conquest's 38mm case is listed at 10.9mm thick and the HydroConquest's 41mm at 11.9mm. A watch that is three millimetres narrower and a millimetre slimmer disappears under a shirt cuff in a way the dive watch will not, and the Conquest's 19mm strap follows the smaller case. The parent listing also offers the Conquest in 41mm, but we captured only the 38mm and cannot vouch for the larger sibling's specifications. For a wrist under roughly 6.75 inches, or for anyone who wears a jacket most days, the 38mm Conquest is the obvious pick; the HydroConquest is the one that reads as a sports watch from across a room.
Which one should you buy? For a first Swiss automatic you will wear to work, buy the Conquest 38mm: slimmer, an exhibition back, a micro-adjust clasp, and 100 metres is plenty for daily life. For a watch that goes in the water on purpose, buy the HydroConquest: 300 metres, a ceramic rotating bezel, and a screw-down crown are the whole point. For a smaller wrist or a shirt cuff, the Conquest. For a larger wrist or a casual wardrobe, the HydroConquest. If you want one Longines that does both jobs adequately, the HydroConquest is the more capable watch and the Conquest is the more refined one — and reasonable collectors disagree about which of those matters more. Both are sold and shipped by Amazon.com with free returns shown, so the wrong choice costs a return rather than a regret.
Bottom Line: Which Should You Buy?
For the water and the weekend: the Longines HydroConquest 41mm Automatic, Sunray Blue, Rubber Strap — 300 metres, ceramic unidirectional bezel, screw-down crown and case back, L888 automatic — the dive watch of the pair.
For the office and the cuff: the Longines Conquest 38mm Automatic, Sunray Blue, Rubber Strap — 38mm and 10.9mm thick with a sapphire exhibition back, micro-adjust clasp and the same L888 calibre, rated to 100 metres.
Ready to buy?
Jump straight to our picks on Amazon — current prices shown at click-through.
Frequently Asked Questions
Is the Longines Conquest a dive watch?
No. The Conquest listing states 100 metres of water resistance, a fixed stainless steel bezel, and a screw-down transparent case back. That is an everyday sports watch that can be swum in, not a diver. The HydroConquest is the collection's dive watch, with 300 metres, a unidirectional rotating bezel, and a screw-down crown and case back.
Do the HydroConquest and Conquest use the same movement?
On these two listings, yes: both state the Swiss automatic L888 calibre with hours, minutes, seconds and date. Neither listing publishes a power reserve or accuracy figure. The Conquest's transparent case back lets you see the movement; the HydroConquest listing describes only a screw-down case back.
What sizes does the Longines Conquest come in?
The listing we captured is the 38mm, and its parent page offers a 41mm option as well. Only the 38mm automatic's specifications are verified here; our best Longines watches guide covers the Conquest Classic quartz pieces separately.
Which is better for a small wrist?
The Conquest 38mm. It is listed three millimetres narrower and a millimetre thinner than the HydroConquest 41mm, on a 19mm strap rather than a 21mm one, which suits wrists under roughly 6.75 inches and sits more easily under a cuff. The HydroConquest in 41mm is the default for most wrists; a 43mm version exists for larger ones.
Where does the 1954 date in the Conquest description come from?
The listing's own description states that the Conquest was the first Longines collection to have its name protected by the Swiss Federal Intellectual Property Office, in 1954. We report that as the listing's claim; nothing else on either page addresses the collections' history.
Related Guides
How We Research
Picks are based on the specifications each live listing publishes, the brand behind it, the seller of record, and the returns terms shown — all captured at the time of research. Listings and stock change — confirm current details at the retailer before buying.
Care and buying note: Rubber straps outlast leather in water but hold sweat and sunscreen — rinse and dry them after a swim, and keep the Conquest's 100-metre rating in mind before a dive. We opened and verified both listings on 19 September 2026 — published specifications, the Longines name, the first-party Amazon.com seller line, and the free-returns line each displayed at capture — and the comparison rests on those documented facts. Confirm current details on the live listing before ordering.