Seiko Prospex Diver's Samurai automatic blue dial steel bracelet 41,7 mm

Samurai Collection DNA

The Seiko Samurai is one of the Japanese brand’s most iconic modern dive watches. First launched in 2004, it immediately stood out thanks to its angular case, sharp lines, and radically contemporary identity, in stark contrast with the round, vintage-inspired models like the Turtle. This sharp design, reminiscent of a katana blade, quickly earned it the nickname “Samurai.”

After an initial run with versions in steel and even titanium (for the Japanese market), the Samurai disappeared before making a strong comeback in 2017 in a larger 43.8 mm version, which won over many tool-watch enthusiasts. In 2020, it received the King Samurai treatment, incorporating premium materials (ceramic bezel, sapphire crystal, improved finishing).

In 2024, for its 20th anniversary, the Samurai underwent a complete redesign. Its case has been fully reworked and reduced to 41.7 mm, its lugs are more fluid, and its dial has been rebalanced with updated hands and indexes. This evolution preserves the Samurai DNA while making it more versatile and comfortable for everyday wear.

The SRPL51K1, with its deep cobalt blue dial, is part of this new generation: a timepiece that retains the angular soul of the Samurai while adopting more contemporary and versatile proportions.

Design & Aesthetics

The Seiko Prospex Samurai SRPL51K1 immediately stands out with its monochromatic blue theme, giving it a unique identity within the 2024 Samurai lineup.

With its 41.7 mm diameter, 12.3 mm thickness, and 49.5 mm lug-to-lug, the SRPL51 adopts a more balanced format than the older 43.8 mm Samurai models. These updated proportions improve wrist ergonomics while maintaining the robustness for which the model is known. The stainless steel case alternates polished and brushed finishes, enhancing its utilitarian yet modern character. The screw-down crown, protected by angular guards, ensures 200 meters of water resistance.

The unidirectional bezel features a blue aluminum insert with white numerals and markings. Its pronounced knurling, typical of the Samurai, allows for a firm grip even when wearing diving gloves. This energetic tone brings a sporty touch while remaining perfectly legible.

The cobalt blue dial delivers a vibrant and elegant look, shifting between subtle and luminous tones depending on the angle of the light. The new elongated pentagonal markers replace the oversized rectangles of the previous generation, creating a more uniform and refined display. The date is positioned at 4:30, preserving the dial’s symmetry and readability.

The hands have also been redesigned:

• The hour hand now features a slimmer lance shape instead of the oversized arrowhead of earlier models.
• The minute hand has been broadened at the base for greater visual impact.
• The seconds hand retains its luminous triangle, now placed closer to the tip for improved precision.

All markers and hands are coated with white LumiBrite, ensuring flawless readability even in complete darkness.

This Samurai is delivered on a three-link stainless steel bracelet, now 20 mm wide, more balanced and better proportioned than older Samurai models. Its beveled links give a more refined appearance, and the folding clasp includes a secure diver’s extension.

Movement & Performance

At the heart of the Seiko Prospex Samurai beats the in-house 4R35 caliber, a movement well known among Seiko enthusiasts.

Technical specifications:

• Type: automatic with manual winding
• Frequency: 21,600 vibrations/hour (3 Hz)
• Jewels: 23
• Power reserve: approximately 41 hours
• Functions: hours, minutes, seconds, date, hacking seconds

Part of a lineage of robust and accessible calibers, the 4R35 is a true workhorse, favoring reliability over refinement. Designed to accompany the watch in all situations, it is appreciated for its durability and ease of maintenance.

Seiko specifies an accuracy tolerance of –35 to +45 seconds per day. In practice, many examples perform more consistently, but the key is the confidence this caliber inspires: a mechanism that starts instantly on the wrist and runs reliably, faithful to the Prospex philosophy.

While some may regret the absence of a technical upgrade (such as the 6R35 with its 70-hour reserve), the 4R35 remains a proven, dependable standard, perfectly suited to a diver in this segment. Combined with 200 meters of water resistance, it makes this toolwatch ready to accompany its wearer both underwater and in everyday life.