Kensington Watches
Rotary Seamatic 300 42mm Mens Watch Black

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Rotary

Rotary Seamatic 300 42mm Mens Watch Black

Ref. RGB05430/04

Among our 159 Rotary watchesThis watch£299
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 159 Rotary watches in stock.

Rotary has been making watches since 1895, but the Seamatic is a deliberate step into serious dive territory — a rated-to-300m tool watch wearing a black ceramic bezel and a matte dial, aimed at buyers who want genuine water credentials without the name-brand premium. The 8215 from Miyota is a dependable workhorse: robust, self-winding, and with a 40-hour power reserve that covers a weekend without winding. At 14mm the case sits thicker than a dress watch but not unusually so for the depth rating, and the three-link bracelet keeps the whole thing coherent — one material, one finish, nothing that reads as an afterthought.

Reference
RGB05430/04
Brand
Rotary
Case size
42mm
Case material
Stainless steel
Case shape
Round
Dial
Black
Crystal
Sapphire
Movement
Automatic
Calibre
Miyota 8215
Functions
Date
Water resistance
300m
Bracelet / strap
Stainless steel bracelet
Strap colour
Silver
Lume
Luminous
Retailer
Goldsmiths
Additional specifications
Power reserve
40 hours
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 (2,762), Automatic Watches (1,400), Back in Stock (820), Sports Watches (687), Dive Watches (480) and Automatic Watches Under £500 (295).

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
  • One of Rotary's more premium watches

Worth knowing

  • 40-hour reserve means winding it after a day off
Best forDivingSwimmingEveryday 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 42mm Mens Watch Black compared with 2 alternatives from other brands
SpecificationThis watchSeamatic 300 42mm Mens Watch BlackRGB05430/04OrientRA-ACOQ11E Mako Automatic Green Silicone Strap Watch - W2999RA-AC0Q11ESeiko5 Sports SRPD55K3 Men's Watch – 42.5mm Black Dial NylonSRPD55K3
Price£299£299£299
Case size42mm39.9mm42.5mm
Water resistance300m200m100m
MovementAutomaticAutomaticAutomatic
StrapStainless steel braceletSilicone strapFabric strap
Power reserve40 hours40 hours41 hours
This watch
  • Rated shallower
  • Wears smaller
  • 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.

How long does it run for when it's not worn?

About 40 hours fully wound — enough to survive a night off the wrist, but not a full weekend.

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 £299. 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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