Seiko Prospex Baby Tuna Street Series Ref. SRPD11J1 / SRPD11K1 (Special Edition Blue/Black)
Dive Watch / ISO 6425 Certified · Seiko (Seiko Group); Mid-range Luxury/Tool Watch tier. Renowned for vertical integration and in-house manufacturing.
Period: Modern Tool Watch / Neo-Vintage (2018-Present). It balances the 1975 Tuna heritage with modern colorways and materials.
Type
Dive Watch / ISO 6425 Certified
Brand
Seiko (Seiko Group); Mid-range Luxury/Tool Watch tier. Renowned for vertical integration and in-house manufacturing.
Movement
Automatic Seiko Caliber 4R36; 21,600 vph, 41-hour power reserve, 24 jewels, hacking and hand-winding capabilities.
Dimensions
Case Diameter: 45mm, Thickness: 13.4mm, Lug-to-Lug: 47mm (very short due to hidden lugs), Lug Width: 22mm. Wears smaller than 45mm due to the lugless shroud design.
Description
A robust and iconic 'Tuna' derivative, this watch offers a modern twist on Seiko’s professional diving heritage. The protective shroud gives it a massive presence, yet its short lug-to-lug distance makes it surprisingly wearable for average wrists. The blue-to-black gradient dial and red bezel accents provide a high-contrast, technical aesthetic suitable for both professional diving and urban wear.
Key Features
External protective shroud, 4 o'clock crown, Short hidden lugs, Wave-patterned gradient dial, and Lumibrite illumination.
Dial Description
Gradient blue sunburst / 'Save the Ocean' wave texture. Features high-visibility applied geometric indices with LumiBrite, broad arrow hands with red accents, and a day-date complication at 3 o'clock.
Case Material
Stainless steel with a blue hard-coated (PVD/DLC) protective outer shroud. The inner case features a mix of brushed and polished surfaces under the shroud.
Crystal Type
Hardlex Mineral Crystal (Seiko proprietary scratch-resistant glass); flat profile.
Bezel Details
120-click unidirectional rotating dive bezel. Two-tone insert: Dark blue and black with red accents for the first 15 minutes of the dive scale.
Crown & Pushers
Screw-down crown located at the 4 o'clock position to prevent wrist bite; textured for grip, stainless steel with blue coating.
Bracelet or Strap
Blue accordion-style silicone diver's strap with stainless steel keeper and buckle. Designed to expand/contract with wetsuit pressure.
Caseback Details
Solid screw-down stainless steel caseback featuring the iconic Seiko Great Wave off Kanagawa medallion engraving.
Movement Type
Automatic Seiko Caliber 4R36; 21,600 vph, 41-hour power reserve, 24 jewels, hacking and hand-winding capabilities.
Water Resistance
200 Meters (660 Feet). Suitable for scuba diving. Features specialized L-shaped gaskets for superior gas resistance without a helium valve.
Origin & Provenance
Japanese design and movement. Depending on the suffix, assembled in Japan (J1) or outside Japan using Japanese parts (K1).
Age Estimate
Circa 2018-2022. Identified by the Prospex 'X' logo and the blue shroud colorway introduced in the late 2010s.
Cultural Significance
Represents the democratization of professional dive tech. The Tuna case silhouette is one of the most recognizable and respected shapes in the global enthusiast community.
Condition Notes
Very Good/Excellent. Minimal visible wear on the shroud; bezel alignment appears correct. Crystal is clear. Strap shows slight dust attraction common for matte silicone.
Value Estimate
$350 - $550 USD depending on region and existence of original box/papers. J1 models command a slight premium over K1 models.
Care & Maintenance
Recommended service interval of 5 years. Rinse with fresh water after salt exposure. Ensure crown is fully screwed down before water entry. Silicone strap can be cleaned with mild soap.
Similar Watches
Seiko SRPE31 'Urban Safari', Seiko SNE533 Solar Tuna, and the high-end Marinemaster Professional SBBN031.
Interesting Facts
The 'Tuna' nickname comes from its resemblance to a tuna tin. The original 1975 Tuna was designed after a diver complained about watches breaking under professional saturation work; it resulted in over 20 patents.