Seiko 62MAS 6217-8000

The Seiko 62MAS 6217-8000, affectionately nicknamed the “Small Crown” 62MAS, holds immense significance as Seiko’s, and Japan’s, first professional dive watch. Launched in April 1965, its production run was remarkably brief, lasting only two to three months (until May or June 1965) before being succeeded by the Ref. 6217-8001 “Big Crown”. This extremely short production window makes it significantly rarer than its successor, with estimates suggesting only around 12,300 units were made. Key features include a 37mm stainless steel case , a 150-meter water resistance rating achieved via gaskets and a screw-down case back , a bidirectional rotating bezel , a distinctive grey sunburst dial with large luminous markers , and the Caliber 6217A automatic movement with a quickset date. Its defining physical characteristic is its smaller 5.5mm crown , which proved difficult for divers to operate and led to its rapid replacement by the “Big Crown” 6217-8001. The 6217-8000 established the foundation for Seiko’s legendary line of dive watches, making it a historically crucial and highly sought-after collector’s piece.  

Specifications

(Note: Dimensions like diameter and thickness can show minor variations across sources.)

Variations and Key Features

The Seiko 6217-8000 is defined by its status as the very first iteration of the 62MAS line, produced for an extremely short period (April-May/June 1965). Its key distinguishing features compared to the later 6217-8001 are primarily related to the crown and case construction.  

Case:

• Material: Stainless steel.  
• Size: Approximately 37mm diameter.  
• Crown: Features the characteristic small 5.5mm crown, signed “Seiko”. This smaller size proved difficult for divers to operate, especially with gloves, leading to its rapid replacement.  
• Crown Tube/Case Design: The case design differs subtly from the 8001 to accommodate the smaller crown. It lacks the longer crown tube, flange, and case recess found on the later “Big Crown” model.  
• Case Back: Features an engraved dolphin motif signifying water resistance. Early 6217-8000 case backs are noted for having a lighter etching compared to the dolphin backs found on early 6217-8001 models, making them prone to wearing down over time.  

Bezel:

• Type: Bidirectional rotating external bezel.  
• Insert: Black aluminum insert with a 60-minute scale and luminous pip at 12. The font used on the bezel insert became a hallmark and influenced later Seiko divers.  
• Edge: Coin-edged for grip. Variations in edge height exist but are not specific to the 8000 reference.  

Dial:

• Color/Finish: Dark grey sunburst dial, often appearing black.  
• Markers: Large, applied rectangular hour markers filled with luminous material (likely tritium, given the era). Markers were embossed for durability.  
• Date: Framed date window at 3 o’clock.  
• Text: Typically signed “Seiko” and “Automatic,” often with water resistance (“Water Proof”) and jewel count (“Diashock 17 Jewels”). “Japan” marking usually present between 6 and 7 o’clock.  

Hands:

• Style: Broad, lume-filled baton hour and minute hands; sweep seconds hand with a rectangular lume plot.  

Crystal:

• Type: Domed acrylic (Plexiglass).  

Movement (Caliber 6217A):

• Type: 17-jewel automatic (self-winding).  
• Frequency: 18,000 bph (2.5 Hz).  
• Features: Quickset date. Non-hacking. Non-manual winding.  

Additional Information

The Seiko 6217-8000 “Small Crown” 62MAS is a historically pivotal watch, marking Seiko’s entry into the professional dive watch arena in 1965. Its design, featuring a rotating bezel, robust case, and legible dial, set the template for many future Seiko divers.  

Its extremely short production run of only two to three months (April-May/June 1965) makes it significantly rarer than the subsequent 6217-8001 “Big Crown” model. Estimates place total production around 12,300 units, roughly 15% of the total 62MAS production. This rarity, combined with its historical importance as Seiko’s first professional diver, makes it highly sought after by collectors.  

The rapid replacement of the 6217-8000 with the 6217-8001 was primarily driven by the functional limitation of the small crown, which was difficult for divers to operate. This quick iteration demonstrates Seiko’s early focus on practical usability in their tool watch designs. While the later 6217-8001 was used by the Japanese Antarctic Research Expedition (JARE) , the 6217-8000 represents the absolute genesis of this iconic lineage. Finding examples in good, original condition is challenging due to both rarity and the tendency for the lightly etched dolphin case back to wear down.