Seiko Prospex Marinemaster

Seiko has announced the global launch of its Prospex Marinemaster watches powered by a slimline automatic movement, the Caliber 6L37.

Seiko Prospex Marinemaster

The Marinemaster is Seiko’s flagship series for diving, equipped with a robust and high-performance movement with stable accuracy designed exclusively for diver’s watches.

Originally launched in the Japanese domestic market, the series has been revitalized and makes its global debut with three new Prospex Marinemaster creations – one limited edition (reference SJE097) and two regular production references, SJE099J1 and SJE101J1.

Seiko Prospex Marinemaster

Representing the official global launch of the Marinemaster line, each new watch takes its design inspiration from the iconic 62MAS of 1965, Seiko’s first watch for divers and the first diver’s watch made in Japan.

A textured horizontal stripe pattern expresses lapping waves on each watch’s dial while adding a stylish touch to the new design, which features “Marinemaster” printed just below the Seiko logo at the 12 o’clock position.

Seiko Prospex Marinemaster SJE097J1 Limited Edition
Marinemaster SJE097J1 Limited Edition

A silvery-white dial graces a limited-edition version commemorating the 100th anniversary of the Seiko brand, while light blue and black dials join the Prospex collection as standard watches.

Seiko Prospex Marinemaster SJE099J1
Marinemaster SJE099J1

Each watch’s hour, minute, and seconds hands inherit the design of those found on the 1965 diver’s watch, with legibility in dark lighting ensured by Lumibrite-filled indexes and a luminous pip on the unidirectional bezel.

Seiko Prospex Marinemaster SJE101
Marinemaster SJE101

The automatic Seiko Caliber 6L37 is the first movement in the slimline Caliber 6L series developed specifically to meet the rigors of diving while allowing a pleasingly slender profile and a high level of comfort on the wrist. Caliber 6L37 has been adapted from the earlier Caliber 6L35 to have greater shock resistance while maintaining the slender profile that characterizes the 6L movement family.

For the first time in a Seiko diver’s watch, the new Marinemaster creations feature an exhibition case back, allowing a view of this finely finished, high-performance mechanical movement.

The new watch needed to maintain the high level of water and shock resistance that Prospex usually achieves with a closed case back while also keeping the profile thin. By reconsidering the case structure and using the slimline Caliber 6L37, Seiko created what is its thinnest mechanical diver’s watch currently (12.3mm) while adding a view of the movement.

The new 39.5mm case design creates a sleeker and more modernized appearance while retaining the essential profile of the classic 62MAS from 1965. The combination of the hairline and mirror finishes on the case and bracelet endows the design with a sophisticated contrast and elegance.

The new Marinemaster comes with an entirely new bracelet that features ellipse-shaped links with mirror-finished, dual-curved surfaces.

Seiko Prospex Marinemaster SJE097J1 Limited Edition

The new Marinemaster watch with a silvery-white dial (reference SJE097/ JDM number SBEN005) will be offered as a limited edition of 1,000 pieces. All three watches will initially be exclusive to Seiko Boutiques, starting in December, and then will be available at select retail partners worldwide in January 2024.

Technical details

Collection: Seiko Prospex Marinemaster


  • Seiko Prospex Marinemaster 1965 Diver’s Modern Re-interpretation: SJE099 (SBEN007) and SJE101
  • Seiko Brand 100th Anniversary, Prospex Marinemaster 1965 Diver’s Modern Re-interpretation Limited Edition SJE097 (JDM reference SBEN005)

Caliber 6L37
Driving system: Automatic
Frequency: 28,800 vibrations per hour(8 beats per second)
Power reserve: 45 hours
Number of jewels: 26
Magnetic resistance: 4,800 A/m

Case and bracelet
Stainless steel case and bracelet with super-hard coating
Stainless steel bracelet with three-fold clasp with push button release, secure lock, and extender
Box-shaped sapphire crystal with anti-reflective coating
See-through screw case back, screw-down crown
Lumibrite on hands and indexes
Diameter: 39.5mm
Thickness: 12.3mm
Length: 47.2mm
Water resistance: 200m diver’s

SJE097: Silver white dial
SJE099: Light blue dial
SJE101: Black dial

SJE099 and SJE101: Non-limited
SJE097: Limited edition of 1,000 watches including 200 pieces in Japan

Recommended retail price
Europe: €3,400
Japan: 429,000 Yen (tax included)