The 1960s is widely known as the golden era for watches, especially for dive watches. As the technology for diving equipment advances, the demand for watches with increased diving capabilities becomes increasingly crucial. As one of the pioneers of dive watches, Seiko holds a rich history in developing reliable and robust timekeeping instruments for the most serious professional divers. Seiko gained enormous respect from divers all around the world, setting a global standard with their advanced horological innovations.


In 1965, Seiko unevilled Japan’s first ever dive watch - the legendary 150 meters automatic Seiko Ref. 62MAS. This paved the way for many incredible Seiko dive watches in the subsequent years that remain iconic even until today. One of the most prominent models would be the highly sought after Seiko Ref. 6159-7001, released in 1968 as Japan’s first hi-beat diver distinguished by the high-frequency caliber that operates at 36,000 beats per hour for greater precision. 


Seiko Prospex 200M Automatic Diver Scuba GMT Green Ref. SBEJ009

The first reiteration of the 6159-7001 came along with Ref. SBDC061 and SBDC063 “Baby MM” which has since been discontinued and replaced with the upgraded “Baby MM Reduced ”Ref. SBDC127 /SBP 187 and Ref. SBDC125 / SPB185 which took design cues from the MM300. Fast forward to 2023, Seiko spiced up its Seiko 5 collection introducing a GMT function powered by the new 4R36 movement.

Riding the GMT wave, Seiko surprised us with the first mechanical GMT diver to the Prospex range with the introduction of SBEJ009. First impressions may seem delusional as the case looks identical to the MM200. On closer inspection one will notice Seiko has once again worked its magic to make the new GMT diver unique.


The  case of the Prospex 200M Automatic Diver Scuba GMT Green Ref. SBEJ009 continues the classic case design reminiscent of the MM300, recognized for its solid shoulders, angular shapes, crown at 4 o’clock, wide bezel, strong lines all around the case beautifully finished with a mix of polished surfaces.

Seiko Calibre 6R54 With 72 Hours Power Reserve

The top of the lugs are meticulously finished with satin brushing that dips downwards to a high polish mirror finish on the side of the case. A streak of brushed finishing across the side of the case divides the polished finishing to create a handsome contrast between the finishes, making the watch look incredibly refined. The detailed finishing carries down to the newly designed 20mm stainless steel bracelet equipped with divers’ extension for quick adjustment on the fly.

The case diameter remains at a modest 42mm in diameter with improved ergonomics and greater emphasis on comfort thanks to the shorter lugs. Fans of Prospex Divers will be pleased that lug to lug has been reduced to 48.6mm and still manages a relatively modest profile of 12.9mm despite the additional GMT function. The watch wears smaller on the wrist than the dimensions suggests, giving the watch an elegant outlook, looking right in place even in dressier occasions. The stainless steel case is coated with Seiko’s proprietary DiaShield hard coating, significantly improving the hardness of the case for protection against accidental scratches. The screw-down crown at the 4 o’clock position with the screw-down case back equips the watch with a ISO-certified 200 meters of water resistance to be a functional companion for underwater adventures. 


Stainless steel, diamond shield case

Zirconia ceramic bezel inserts has been used exclusively on elite Prospex divers. The Prospex 200M Automatic Diver Scuba GMT Green Ref. SBEJ009 joins this segment with a green zirconia ceramic bezel insert that resembles the insert first introduced on the  MM300 “Deep Forest” SBDX021 with featuring a lusher hue. Mated to a 120-click unidirectional diving bezel finished with white makers and numerals exerting a glossy shine for an opulent look .

The opulent look transcends to the dial with matching sunburst green retaining the iconic layout of the Seiko Ref. 6159-7001 with large visible indexes and broad hands that are filled with Seiko’s famed Lumibrite that glows like a torch in the dark. In order to retain a 60 minute dive bezel , a 24 hour scale has been added on the inner flange that functions together with the central 24 hour hand. Protecting the dial sits a piece of sapphire crystal with anti-reflective coating on the underside.

Seiko's LumiBrite at its best

Under the impressive exterior of the Prospex 200M Automatic Diver Scuba GMT Green Ref. SBEJ009 lies the new Seiko 6R54 movement, which is equipped with 72 hours of power reserve. The central 24 hour hand can be set independently and functions as the “Travel Time”. The 24 jewel movement has a 3 Hz beat rate of 21,600 beats per hour.

This new addition to the Prospex line is a milestone for Seiko featuring new form and function made to the highest standards of Japanese watchmaking Seiko is best known for. The Prospex 200M Automatic Diver Scuba GMT Green Ref. SBEJ009 brings forth a timeless design with contemporary upgrades that truly makes this watch a beast challenging the likes of the Iconic MM300 with a modest budget.