SEIKO PROSPEX SRPF03K1 - ‘SAMURAI’ Automatic Diver

The Seiko Prospex SRPF03K1 is a rugged, reliable automatic diver’s watch from Seiko’s Prospex “Samurai” series — named by enthusiasts for its bold, angular case lines that resemble a Samurai sword’s edge. Built for both everyday wear and aquatic adventure, it pairs a proven mechanical movement with classic dive-ready features.

Key Features

• Automatic Mechanical Movement – Caliber 4R35
  A self-winding movement with manual winding capability and stop-seconds for precise time setting.
• 41-Hour Power Reserve
  Keeps running for around 41 hours when fully wound.
• 200 m Water Resistance (ISO-rated)
  Suitable for recreational scuba diving and water activities.
• Unidirectional Rotating Bezel
  Essential for timing dives and elapsed intervals.
• LumiBrite Hands & Indices
  Strong luminescent coating for clear visibility in low light.
• Date Display at 3 o’clock
  Practical calendar window integrated into the dial.

Specifications

Movement

• Calibre: Seiko 4R35 — automatic with manual winding and stop seconds
• Jewels: 23
• Power Reserve: Approx. 41 hours

Case & Bracelet

• Case Material: Stainless steel
• Bracelet: Stainless steel with three-fold clasp + secure lock + extender
• Crystal: Hardlex (Seiko-tempered mineral crystal)
• Case Diameter: 43.8 mm
• Case Thickness: 13.4 mm
• Lug Width: 22 mm
• Weight: ~201 g (steel bracelet)

Durability & Water Resistance

• Water Resistance: 200 m / 20 bar — suitable for recreational scuba diving and water sports.
• Bezel: Unidirectional rotating for dive timing.
• Crown: Screw-down for enhanced sealing.
• Caseback: Screw caseback for water integrity.

Dial & Hands

• Dial Color: Black with textured pattern and high-contrast markers
• Hands & Markers: Silver-tone with LumiBrite luminous coating
• Seconds Hand: Often with a contrasting red tip for visibility

Functions:

• Hours, Minutes, Seconds
• Date display
• Stop-seconds hand function

The SRPF03K1 embodies the Samurai identity: sharp, angular case lines and a robust diver profile that distinguishes it from more rounded dive watches. Its LumiBrite-enhanced dial, secure bracelet, and classic rotating bezel make it both a reliable tool in the water and a versatile everyday piece.

The Seiko Prospex SRPF03K1 “Samurai” Automatic Diver is a great choice if you want a automati mechanical diver with a strong tool aesthetic. With its solid 200 m water resistance, dependable Calibre 4R35 movement, and classic dive features — all wrapped in durable stainless steel — it’s a capable and attractive tool watch for both underwater and daily wear