Tissot Seastar Watch Guide
This is a supporting guide to our main Tissot Brand Guide. It focuses specifically on the Seastar collection — its heritage, depth ratings, sizing, and how to choose the right model.
1 | Overview
The Tissot Seastar is the brand's dedicated dive watch collection, offering professional-grade water resistance and construction at accessible Swiss price points.
The Seastar name dates back to 1952, originally denoting water-resistant dress watches before evolving into a full dive watch family. Today's collection spans from compact 36mm quartz models to the ISO 6425-certified Seastar 2000 Professional — a 600-metre saturation diver.
Standard Features Across All Seastars
- Sapphire crystals
- Screw-down crowns
- Unidirectional rotating bezels
2 | Collection Origin
The Seastar trademark was registered on 13 December 1952. In its earliest form, “Seastar” was a functional descriptor applied to water-resistant models, most notably the Visodate Seastar T-12 of the late 1950s.
These early models were not dive watches in the modern sense. They were robust dress watches capable of withstanding swimming and humid conditions, typically featuring 35mm cases, dauphine hands, and screw-down case backs engraved with the Tissot galleon ship.
3 | Model Hierarchy
| Model | Case Size | Depth Rating | Movement | Bezel |
|---|---|---|---|---|
| Seastar 1000 Quartz | 36mm / 40mm | 300m | PreciDrive Quartz | Ceramic |
| Seastar 1000 Powermatic | 40mm | 300m | Powermatic 80 | Mineral |
| Seastar 1000 Powermatic | 43mm | 300m | Powermatic 80 | Ceramic |
| Seastar 2000 Professional | 46mm | 600m | Powermatic 80 | Ceramic |
4 | Water Resistance & ISO 6425
Seastar 1000 (300m / 30 bar)
Suitable for recreational diving, swimming, and water sports. Screw-down crowns and case backs. Not individually ISO 6425 certified but tested for water resistance.
Seastar 2000 Professional (600m / 60 bar)
Fully ISO 6425 certified. Each watch tested to 125% of rated depth (750m equivalent). Automatic helium escape valve at 9 o'clock. Mandated shock and magnetic resistance benchmarks.
Which Do You Need?
The helium escape valve is relevant only for saturation diving with helium-rich gas mixtures. For recreational diving, swimming, and daily wear, the standard Seastar 1000 exceeds requirements.
5 | Case Architecture & Sizing
| Model | Diameter | Lug-to-Lug | Thickness | Recommended Wrist |
|---|---|---|---|---|
| Seastar 1000 (36mm) | 36mm | ~42mm | ~11mm | 5.5–6.5" |
| Seastar 1000 (40mm) | 40mm | ~46mm | ~12.5mm | 6.25–7.5" |
| Seastar 1000 (43mm) | 43mm | ~50mm | ~12.5mm | 7+" |
| Seastar 2000 Pro | 46mm | ~52mm | ~16.25mm | 7.5+" |
Fit Notes
- The 43mm has straight lugs that can overhang wrists under 7 inches
- The 40mm (2024) has shorter lugs and a notched case profile reducing visual mass
- The Seastar 2000 Professional is designed for diving wetsuits — on bare wrist it wears large (~200g on bracelet)
6 | Bezel Materials
Ceramic (Zirconium Oxide)
Used on the 36mm quartz, 43mm automatic, and Seastar 2000 Professional. Virtually scratch-proof, UV-resistant, maintains appearance over decades. Numerals engraved and filled with paint or Super-LumiNova.
Mineral Glass
Used on the 40mm Powermatic 80. Glossy, vintage aesthetic reminiscent of early dive watch bezels. Softer than ceramic (5–6 Mohs vs 9) and will accumulate scratches — a deliberate aesthetic choice prioritising vintage character.
7 | Movement Specifications
Powermatic 80 (Automatic)
Based on ETA 2824-2 architecture. 80-hour power reserve at 3Hz (21,600 vph). Nivachron balance spring for magnetic resistance. Exhibition caseback on most models.
PreciDrive (Quartz)
Thermocompensated quartz adjusting for temperature variation. Accuracy: ±10 seconds per year. HeavyDrive technology prevents hand misalignment during impacts. End-of-life battery indicator.
8 | Care & Ownership
Seastar Care Essentials
- Rinse with fresh water after saltwater or chlorine exposure
- Have water resistance tested annually if used for regular swimming or diving
- Automatic models benefit from servicing every 4–5 years
- All models supplied with 2-year international warranty
For general watch care guidance, see our Watch Care Guide.
Shop Seastar at OD's
Top Picks at OD's — In Stock Now
Three best-sellers our customers are choosing this month — all in stock, ready to ship from St Helens, available to try in our St Helens store before you buy.
All available in-store at 41 Barrow Street, St Helens, WA10 1RY — try before you buy.
Browse the full jewellery range at OD's.
9 | Frequently Asked Questions
Do I need the Seastar 2000 Professional for recreational diving?
No. The standard Seastar 1000 with its 300m depth rating exceeds the requirements of recreational diving (maximum 40m). The Seastar 2000 Professional with its 600m rating and ISO 6425 certification is designed for professional saturation diving with helium-rich gas mixtures.
What is the difference between ceramic and mineral bezels?
Ceramic bezels (zirconium oxide) are virtually scratch-proof and UV-resistant, maintaining their appearance for decades. Mineral glass bezels have a glossy, vintage aesthetic but are softer (5–6 Mohs vs 9 for ceramic) and will accumulate scratches with use. The mineral option is a deliberate style choice, not a cost compromise.
Which Seastar size should I choose?
The 36mm suits wrists 5.5–6.5 inches. The 40mm is the sweet spot for 6.25–7.5 inch wrists with shorter lugs that reduce overhang. The 43mm suits 7+ inch wrists but has straight lugs that can overhang smaller wrists. Try on in-store at OD's for the best comparison.
How accurate is the PreciDrive quartz movement?
PreciDrive is thermocompensated, adjusting for temperature variation to deliver accuracy of ±10 seconds per year — significantly better than standard quartz movements. It also features HeavyDrive technology to prevent hand misalignment during impacts.