Longines HydroConquest vs Tissot Seastar 2000
Longines Hydroconquest L3.742.4.56.6 vs Tissot Seastar 2000 T1206071104100, compared on the specs each brand publishes.
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The short answer
Two Swatch Group dive watches, compared on published specs.
- Case size: the Tissot Seastar 2000 T1206071104100 is 5 mm larger (46 mm vs 41 mm).
- Thickness: the Tissot Seastar 2000 T1206071104100 is 4.35 mm thicker (16.25 mm vs 11.9 mm).
- Water resistance: the Tissot Seastar 2000 T1206071104100 is 300 m more (600 m vs 300 m).
- Power reserve: the Tissot Seastar 2000 T1206071104100 is 8 hours longer (80 h vs 72 h).
- Price: the Tissot Seastar 2000 T1206071104100 lists for $325 less in the US ($1,275 vs $1,600).
Side-by-side specs
| Spec | Longines Hydroconquest L3.742.4.56.6 | Tissot Seastar 2000 T1206071104100 |
|---|---|---|
| Case diameter | 41 mm | 46 mm |
| Thickness | 11.9 mm | 16.25 mm |
| Lug-to-lug | 51.1 mm | Not published by Tissot |
| Lug width | 21 mm | 22 mm |
| Calibre | L888.5 | Not stated |
| Movement | Automatic | Automatic |
| Power reserve | 72 h | 80 h |
| Water resistance | 300 m | 600 m |
| Crystal | Sapphire | Sapphire |
| Case material | Stainless steel | Stainless steel |
| Ships on | Bracelet | Bracelet |
| Weight | 195.1 g | 206 g |
| US list price | $1,600 (US list) | $1,275 (US list) |
| Dial | Sunray black | Blue gradient |
| Status | In production | In production |
| Suits wrists of about our sizing guide | 17.3–18.3 cm | 18.5–20.4 cm |
Specs summarised in our own words from the brand's product pages: L3.742.4.56.6 source (checked 3 Nov 2026) T1206071104100 source (checked 3 Nov 2026). "Not published" means the brand page we checked doesn't list it, so we leave it blank rather than guess.
All the differences
- Case size: the Tissot Seastar 2000 T1206071104100 is 5 mm larger (46 mm vs 41 mm).
- Thickness: the Tissot Seastar 2000 T1206071104100 is 4.35 mm thicker (16.25 mm vs 11.9 mm).
- Water resistance: the Tissot Seastar 2000 T1206071104100 is 300 m more (600 m vs 300 m).
- Power reserve: the Tissot Seastar 2000 T1206071104100 is 8 hours longer (80 h vs 72 h).
- Price: the Tissot Seastar 2000 T1206071104100 lists for $325 less in the US ($1,275 vs $1,600).
- Lug width: Longines Hydroconquest L3.742.4.56.6 has 21 mm; Tissot Seastar 2000 T1206071104100 has 22 mm.
Wrist fit
Lug-to-lug decides overhang more than diameter does. Enter your wrist to see how each one should wear.
- Longines Hydroconquest L3.742.4.56.6 –
- Tissot Seastar 2000 T1206071104100 –
Same rule of thumb as Watch Finder: case diameter of about 23.5% of your wrist circumference (−2 mm to +2.5 mm), and lug-to-lug no longer than about 29% of it plus 1 mm. A guide, not a rule; flat or round wrists differ.
Strap fit
The Longines Hydroconquest L3.742.4.56.6 has 21 mm lugs. The Tissot Seastar 2000 T1206071104100 has 22 mm lugs. A strap bought for one won't fit the other. Size charts: Longines lug width chart · Tissot lug width chart.
Which should you buy?
It is the more compact case on paper (46 mm across). Our sizing guide puts it at about 18.5–20.4 cm.
It has the lower US list price, $1,275, a $325 difference.
It has the higher water-resistance rating: 600 m vs 300 m.
It is the slimmer case at 11.9 mm.
It has the longer published power reserve: 80 h.
Prices and where to buy
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More: All Longines Conquest references · All Tissot Seastar references.
Questions
Which is bigger, the Longines Hydroconquest L3.742.4.56.6 or the Tissot Seastar 2000 T1206071104100?
Per the brands, the Longines Hydroconquest L3.742.4.56.6 is 41 mm across and the Tissot Seastar 2000 T1206071104100 is 46 mm.
Which is cheaper?
The Tissot Seastar 2000 T1206071104100, at a US list price of $1,275 vs $1,600 when we checked.
Which is more water-resistant?
Longines Hydroconquest L3.742.4.56.6: 300 m. Tissot Seastar 2000 T1206071104100: 600 m.
Have you tested these watches?
No. This comparison uses brand-published specs and our own analysis of them, not hands-on testing.
Watch.co is independent and not affiliated with any brand. We haven't handled these watches for this page: everything here comes from brand-published specs and our own analysis. Brand names are used only to identify products.