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Rotary Seamatic 300 GMT 42.5mm Mens Watch Black
Ref. GS04378/95
Sits in Rotary’s upper tier here — more premium than three quarters of the Rotary watches we list, which start at £97.
Price range £97 to £329 across 156 Rotary watches in stock.The Seamatic 300 is Rotary's answer to the traveller who actually dives: a full 300m-rated tool watch with a GMT complication so the second time zone goes on the wrist rather than the phone. The red and blue bi-directional bezel is the tell — it keeps the watch readable in both hemispheres and gives the dial the kind of purposeful colour that comes from function rather than decoration. At 14mm the case sits flatter than the rating might suggest, and on a 22mm silicone strap it sheds water and dries fast. The matte black dial is built for legibility at depth, with the GMT hand providing the extra layer of information a diver who crosses time zones will actually use between trips.
- Reference
- GS04378/95
- Brand
- Rotary
- Case size
- 42mm
- Case material
- Stainless steel
- Case shape
- Round
- Dial
- Black
- Crystal
- Sapphire
- Bezel
- Bidirectional rotating
- Movement
- Automatic
- Functions
- GMT
- Water resistance
- 300m
- Bracelet / strap
- Silicone strap
- Strap colour
- Black
- Lume
- Luminous
- Retailer
- Goldsmiths
Learn more about Rotary
Moise Dreyfuss started Rotary in La Chaux-de-Fonds in 1895. Within a generation his sons Georges and Sylvain had opened a London office and begun exporting to Britain, which turned out to be the decision that defined the company: Britain became, and remains, Rotary's most important market.
The winged wheel logo arrived in 1925 and has barely changed since. It became familiar enough in British high streets that the brand is widely taken for British, despite the Swiss origin.
Rotary supplied watches to the British Army, and the wartime and post-war association gave it a foothold in a market where an affordable, dependable Swiss watch was exactly what most buyers wanted.
The family held the company for over a century, making it for a long time the oldest family-owned Swiss watchmaker still trading. Ownership passed to Hong Kong's Citychamp in 2014, and in February 2025 to the UK's Peers Hardy Group.
The modern range sits at the accessible end — quartz and automatic dress watches, divers and chronographs, with the Henley, Windsor and Legacy lines carrying the collection.
- 1895
- Founded in La Chaux-de-Fonds by Moise Dreyfuss.
- 1920s
- Georges and Sylvain Dreyfuss begin exporting to Britain.
- 1925
- The winged wheel logo is introduced.
- 2014
- Acquired by Citychamp after more than a century in family hands.
- 2025
- Bought by the UK's Peers Hardy Group.
Also in 6 collections
This watch appears in Back in Stock (4,405), Stainless Steel Watches (2,927), Automatic Watches (1,634), Sports Watches (729), Dive Watches (521) and Automatic Watches Under £500 (315).
Temporarily out of stock
Goldsmiths is not currently taking orders for this reference. Last listed as available on 26 September 2026. Stock is checked nightly and this page updates when it returns.
What the specifications mean
A mechanical watch built to be worn hard and got wet.
Strengths
- 300m water resistance, rated for actual diving
- Sapphire crystal, which resists scratching
- Luminous hands and markers for low light
- Second time zone for travelling
- One of Rotary's more premium watches
Rotary Seamatic 300 GMT alternatives
Watches from other brands at a similar price, style and size, so you can see what else your budget can buy.
| Specification | GS04378/95 | RA-AC0Q10N | R8823118012 |
|---|---|---|---|
| Price | £299 | £299 | £299 |
| Case size | 42mm | 39.9mm | 42mm |
| Water resistance | 300m | 200m | 100m |
| Movement | Automatic | Automatic | Automatic |
| Strap | Silicone strap | Silicone strap | Mesh bracelet |
| Power reserve | — | 40 hours | — |
| This watch |
|
|
Your new watch
Frequently asked questions, and things you should know about this watch
Can I swim with it?
Yes. At 300m it is rated for swimming, snorkelling and recreational diving.
Water resistance explainedWill the glass scratch?
Unlikely. Sapphire is second only to diamond in hardness and shrugs off everyday marking.
Sapphire, mineral and acrylic comparedDoes it need a battery?
No. It is automatic — the motion of your wrist winds it, and there is no cell to replace.
Quartz, automatic and solar comparedIs it a men's or women's watch?
Listed as men's.
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