Kensington Watches
Rotary Seamatic 300 GMT 42mm Mens Watch Black

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Rotary

Rotary Seamatic 300 GMT 42mm Mens Watch Black

Ref. GB04378/95

Among our 152 Rotary watchesThis watch£329
Premium

Sits in Rotary’s upper tier here — more premium than three quarters of the Rotary watches we list, which start at £76.

Price range £76 to £349 across 152 Rotary watches in stock.

The Seamatic 300 is Rotary's case for the working diver who also crosses time zones — a combination that sounds obvious but demands real discipline from the movement and the case design together. The GMT function tracks a second time zone via the red-and-blue bezel and a dedicated hand, so arrivals and departures read at a glance without adjusting the main time. At 42mm with a 22mm lug width, it wears as a serious tool watch should: present on the wrist, not delicate. The matte black dial is set up for legibility first, and the bi-directional bezel gives the 300-metre depth rating practical meaning rather than decorative ambition.

Reference
GB04378/95
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
Stainless steel bracelet
Strap colour
Silver
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.

All Rotary watches

Also in 6 collections

This watch appears in Stainless Steel Watches (2,616), Automatic Watches (1,362), Sports Watches (675), Dive Watches (469), Automatic Watches Under £500 (260) and GMT Watches (178).

Manufacturer’s guarantee

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
Best forDivingSwimmingTravelEveryday wear

Compare alternatives

Watches from other brands at a similar price, style and size, so you can see what else your budget can buy.

Seamatic 300 GMT 42mm Mens Watch Black compared with 2 alternatives from other brands
SpecificationThis watchSeamatic 300 GMT 42mm Mens Watch BlackGB04378/95OrientRA-AA0003R39B Mako III Automatic Bracelet Watch - W2942RA-AA0003R39BSeiko5 Sports SRPD65K1 Men's Watch – 42.5mm Black Dial Stainless SteelSRPD65K1
Price£329£385£329
Case size42mm41.8mm42.5mm
Water resistance300m200m100m
MovementAutomaticAutomaticAutomatic
StrapStainless steel braceletStainless steel braceletStainless steel bracelet
Power reserve40 hours
This watch
  • Costs more
  • Rated shallower
  • Rated shallower

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.

Will the glass scratch?

Unlikely. Sapphire is second only to diamond in hardness and shrugs off everyday marking.

Does it need a battery?

No. It is automatic — the motion of your wrist winds it, and there is no cell to replace.

Is it a men's or women's watch?

Listed as men's.

Cheapest place to buy

Goldsmiths is the only UK retailer we track stocking this reference new, at £329. There is nothing to compare it against today.

Who are Goldsmiths?

Goldsmiths has been selling watches in Britain since 1778 and is part of the Watches of Switzerland Group, which is listed on the London Stock Exchange. They are an authorised dealer, so a watch comes with the manufacturer’s own warranty.

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