Heimdallr Monster 'Yellow Shark' (Seiko Monster Homage)
Dive Watch · Heimdallr (owned by Shenzhen XingZhen Industrial Co., Ltd.); Tier: Affordable/Enthusiast 'Homage' brand known for high spec-to-price ratios.
Period: Modern Tool Watch (2010s-Present); specifically a 'homage' to the Mid-Century influenced 1st and 2nd Gen Seiko Monsters.
Type
Dive Watch
Brand
Heimdallr (owned by Shenzhen XingZhen Industrial Co., Ltd.); Tier: Affordable/Enthusiast 'Homage' brand known for high spec-to-price ratios.
Movement
Automatic, Seiko (SII) Caliber NH36; 21,600 bph, 41-hour power reserve, 24 jewels, hacking and hand-winding capabilities.
Dimensions
Case diameter: 42-43mm (excluding crown), Thickness: 13.5-14mm, Lug-to-Lug: 47-48mm, Lug width: 20mm.
Description
The Heimdallr Monster is a robust 'homage' to the legendary Seiko SKX781/SRP307 line. It captures the aggressive, industrial aesthetic that earned the original the 'Monster' nickname, but upgrades the traditional specifications with a sapphire crystal and an NH36 movement. This specific yellow-dial version is a nod to the rare 'Yellow Monster' limited editions, offering high visibility and a playful, tool-watch personality.
Key Features
Aggressive concave bezel; 4 o'clock crown; 'shark tooth' indices; sapphire crystal upgrade over original Seiko Hardlex; shark logo at 12.
Dial Description
Bright yellow matte dial with a shark logo at 12 o'clock; large applied 'shark tooth' indices with green Super-LumiNova; black-framed broad-arrow hour hand and sword-style minute hand; day-date window at 3 o'clock.
Case Material
316L Stainless Steel with a mix of brushed and polished finishes; features a recognizable 'shrouded' design.
Crystal Type
Flat sapphire crystal with anti-reflective (AR) coating.
Bezel Details
Unidirectional 120-click rotating bezel; stainless steel with engraved black numerals and markings (0-60 scale); recessed lume pip at 12.
Crown & Pushers
Screw-down crown located at the 4 o'clock position; features knurled texture for grip; protected by integrated case guards.
Bracelet or Strap
Black vented polyurethane (diver style) strap with stainless steel buckle and keepers; mimics the Seiko 'Z20' style.
Caseback Details
Solid screw-down stainless steel caseback; typically features an engraved shark logo or 'Heimdallr' branding.
Movement Type
Automatic, Seiko (SII) Caliber NH36; 21,600 bph, 41-hour power reserve, 24 jewels, hacking and hand-winding capabilities.
Water Resistance
Rated at 200m (20 ATM); suitable for swimming, snorkeling, and recreational scuba diving if the screw-down crown is fully secured.
Origin & Provenance
China; manufactured in the Guangdong province; utilizes a Japanese-made Seiko NH36 movement.
Age Estimate
Modern production, likely manufactured between 2020 and 2024.
Cultural Significance
Represents the 'Homage' movement in modern watch collecting, where Chinese manufacturers provide enthusiasts with access to the aesthetics of discontinued or expensive tool watches at an accessible price point.
Condition Notes
Appears to be in Mint/New-with-tags condition; factory protective plastic is still visible on the case, bezel, and strap.
Value Estimate
$140 - $180 USD (New/Secondary Market). Value remains stable due to its popularity as a budget-friendly modding platform.
Care & Maintenance
Recommended service every 5-7 years for the NH36 movement; check gaskets annually if used for diving; rinse with fresh water after salt exposure.
Similar Watches
Seiko SKX781 (Orange Monster), Seiko SRP315 (2nd Gen Monster), San Martin Monster, Steeldive SD1952.
Interesting Facts
Heimdallr is part of a wave of 'Ali-Express' brands that gained popularity by offering discontinued Seiko designs with upgraded materials like sapphire and ceramic for under $200.