Seiko Prospex Marinemaster 300 42.6mm SLA079J1

In 1968, Seiko introduced a new and revolutionary innovation with the world's first Hi-Beat dive watch. Featuring a case design inspired by the original 1968 model and carrying the name "Marinemaster" from Seiko's tradition in producing dive watches, this new reinterpretation maintains the same 300-meter water resistance.

Beneath a double-curved sapphire crystal lies a black dial with a subtle sand-like pattern. Designed for high contrast underwater, every aspect is optimized for diving conditions: an aerodynamic case with the crown positioned conveniently at 4 o'clock, strong Lumibrite for readability in the darkest depths, and a unidirectional rotating bezel according to ISO dive standards.

Specifically designed for divers, the 8L35 caliber is a highly precise, reliable, and robust movement. Made at the Shizukuishi Watch Studio in Iwate Prefecture, Japan, this caliber has an accuracy of +15/-10 seconds per day with a power reserve of 50 hours.

Prospex is a combination of the words "Professional" and "Specifications." Seiko Prospex watches are designed to be practical, reliable, and durable; meeting the rigorous standards required in extreme environments for sports enthusiasts and adventurers.

Movement

• Caliber: 8L35
• Type of Movement: Automatic with manual winding capability
• Accuracy: +15 to -10 seconds per day
• Power Reserve: Approximately 50 hours
• Number of Jewels: 26
• Functions:
  • Second hand stop function

Case/Bracelet

• Case Material: Stainless steel
• Case Dimensions:
  • Thickness: 13.4mm
  • Diameter: 42.6mm
  • Lug-to-Lug: 49.3mm
• Crystal: Double-curved sapphire
• Crystal Coating: Anti-reflective coating on the inner surface
• LumiBrite: LumiBrite on hands, markers, and bezel
• Clasp: Triple folding clasp with safety lock, push-button release with extension
• Lug Width: 20mm

Other Details

• Water Resistance: Diver's 300 m/1000 ft
• Magnetic Resistance: 4,800 A/m
• Weight: 196.0g

Features

• Unidirectional rotating bezel
• Screw-down crown
• Triple folding clasp with safety lock
• Screw-down case back