Quick facts
- Caliber
- 6217(automatic)
- Jewels
- 17
- Beat rate
- 18,000 vph
- Hacking / hand-winding
- No / No
- Water resistance
- WATER PROOF
- Crown
- 3 o’clock
- Production
- 1965–1968
- Modern equivalent
- SPB451 / SPB453
Variants
The 8000 and 8001 share the movement and dial code. The crown, the crown tube and the case side around it tell them apart.
| Reference | Market | Day wheel | Status |
|---|---|---|---|
| 6217-8000 | — | — | Pending verification |
| 6217-8001 | — | — | Pending verification |
Serial decoder
The 62MAS dates from 1965 to 1968, when Seiko was moving from seven-digit to six-digit serials. Until we confirm which format these case backs use, the date finder on this page is off.
The 62MAS window: production from April 1965 to early 1968 (Plus9Time, The Seiko Guy, Adventures in Amateur Watch Fettling). The 6217 caliber itself started earlier, in the 1964 6217-7000 World Time; see data/calibers.json.
Possible production date, not a guaranteed date or an authentication. Production date is not the purchase date.
Full decoder with caliber and case codePrice guide
Prices appear after our first sampling of sold listings in November 2026.
| Condition | Low | Median | High |
|---|---|---|---|
A · Collector | — | — | — |
B · Serviced original | — | — | — |
C · Running, unserviced | — | — | — |
D · Project or suspected franken | — | — | — |
Sampled —, n = —, eBay sold listings viewed manually.
Checks before you buy
Expect some replaced parts on a 60-year-old diver. The job is to find out which ones, and whether the seller says so.
Crown, tube and case side The 8000 has a small crown at 3; the 8001 a larger crown with a longer tube and a matching recess in the case. Both are signed.
A crown that doesn't match the tube and case. Seiko's parts book gave both crowns one part number, so a big crown on an 8000 can be a later service part; ask.
Sources: Ikigai; The Watch Bloke. Our own photo comes with our first shoot.
Case back A lightly etched dolphin on the 8000; a dolphin or a horseshoe layout on the 8001.
A back that doesn't fit the reference. A worn-smooth dolphin is common and isn't proof of a swapped back.
Sources: Ikigai; Adventures in Amateur Watch Fettling. Our own photo comes with our first shoot.
Dial Gray dial with applied, framed markers and JAPAN 6217-8000T at the bottom.
Repainted or relumed dials; ask for close-ups of the printing.
Sources: The Seiko Guy; Fratello. Our own photo comes with our first shoot.
Hands and lume Broad baton hands and a seconds hand with a rectangular lume pip.
Replaced or relumed hands. Shapes are shared with other Seikos, so look for a record of what was changed.
Sources: Ikigai; The Watch Bloke. Our own photo comes with our first shoot.
Movement and setting A 17-jewel 6217A, automatic only, with a date quickset.
Hand-setting or the quickset slipping (a worn clutch or setting lever), or a movement loose in the case.
Sources: The Watch Bloke; Adventures in Amateur Watch Fettling. Our own photo comes with our first shoot.
Common faults and service
The faults repairers document on 62MAS watches are in the setting parts and the seals.
Worn clutch or setting wheel lever teeth make hand-setting or the date quickset slip (The Watch Bloke; Adventures in Amateur Watch Fettling)
Hardened crown and case back gaskets and corroded gasket seats (The Watch Bloke; Adventures in Amateur Watch Fettling)
A loose movement from missing or worn casing screws (The Watch Bloke; Adventures in Amateur Watch Fettling)
Slipping hand-setting or date quickset from a worn clutch or setting lever
Hardened crown and case back gaskets with corroded seats
A movement loose in the case from missing casing screws
A seized bezel full of old dirt
Seiko USA doesn't list the 6217 among calibers it won't service, but warns other old calibers may be returned unrepaired. Treat any 1960s diver as not water-resistant until it's been pressure-tested.
Not on Seiko USA's list of calibers not to send (checked 2026-10-26). Seiko USA notes other old calibers not listed may also be returned unrepaired.
Where to look
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When was the Seiko 62MAS released?
In 1965. Seiko Museum calls the 1965 diver Japan’s first 150 m water-resistant watch, and Seiko calls it its first diver’s watch. Adventures in Amateur Watch Fettling dates the small-crown 6217-8000 to April 1965 for about two months; the big-crown 6217-8001 took over in July 1965 and ran until early 1968. The Seiko Guy notes the 62MAS had gone from Seiko’s catalog by the second 1968 volume. The 6105-8000 replaced it.
What does 62MAS mean?
62 comes from the first two digits of the 6217 caliber, and MAS from automatic self-dater, an automatic with a date. Fratello and WorldTempus both explain it this way. 62MAS 010 was the watch’s code in Seiko’s Japanese catalog; the export version was 65134 (The Seiko Guy).
6217-8000 vs 6217-8001: small crown and big crown
The crown is the quick tell, but check the crown tube and the case side too. The big-crown 8001 has a longer tube and a recess in the case around it, so a big crown fitted to an 8000 case looks wrong if you know where to look (Ikigai, The Watch Bloke). The Watch Bloke found both crowns under the same part number in Seiko’s parts book, so a big crown on an 8000 may be a later service replacement rather than a fake; ask.
The case backs differ too. The 8000 has a lightly etched dolphin that wears away easily. The 8001 comes with a dolphin or a horseshoe layout, so a missing dolphin doesn’t prove a swapped back (Ikigai; Adventures in Amateur Watch Fettling). Both references carry the same dial code, JAPAN 6217-8000T.
Specs
The 6217A is a 17-jewel automatic beating at 18,000 vibrations per hour, with a date and quickset. It doesn’t hack and can’t be hand-wound (The Seiko Guy). The case is steel with 19 mm lugs, an acrylic crystal, a bezel that turns both ways without clicks, and a signed crown at 3. Rated to 150 m when new.
Published diameters range from 37 mm (Fratello) through 37.5 mm (Ikigai) to 38.2 mm (The Seiko Guy). Seiko says its 2023 SJE093 re-creation matches the original’s diameter at 38.0 mm. We’ll measure our own.
The Antarctic connection
Seiko Museum records that the 1965 diver was adopted by the 8th Japanese Antarctic Research Expedition, and Seiko says expedition members wore it from 1966 to 1969. The Seiko Guy notes it wasn’t part of the equipment of the previous expedition, which left in November 1965, so don’t date the Antarctic link to the launch year.
Fakes, mods and modern versions
Search eBay for 62MAS and you’ll see modern homages and 62MAS-style mods next to the real thing. An original has a 6217 movement, a 6217-8000 or 6217-8001 case back and the 6217-8000T dial code. Relumed dials and replaced hands turn up on originals too, and some 62MAS hand shapes were used on other Seikos, so ask for a record of what’s been changed (Ikigai; The Watch Bloke).
Plus9Time found that Seiko’s 1965 and 1966 catalogs show the 62MAS on a Tropic-style basket-weave strap. The ZLM01 waffle strap often sold with them came later.
Seiko has re-made the watch several times: the SLA017 re-creation in 2017, the SPB143 re-interpretation in 2020, the SJE093 re-creation in 2023, and the SPB451 and SPB453 that replaced the SPB143 in 2024. Our 62MAS vs SPB143 comparison sets them side by side.
What goes wrong with a 62MAS
The Watch Bloke and Adventures in Amateur Watch Fettling both record worn clutch and setting lever teeth that make hand-setting or the date quickset slip, hardened crown and case back gaskets with corroded seats, and movements loose in the case from missing casing screws. One had a bezel seized with old dirt.
Seiko USA doesn’t list the 6217 among the calibers it no longer services, but warns other old calibers may be returned unrepaired. Treat any 1960s diver as not water-resistant until it has been pressure-tested.
Sources
- Seiko Museum, Diver’s Watch (1965), and Seiko’s 2017 SLA017 announcement: first diver, Antarctic expedition.
- The Seiko Guy, Seiko 62MAS Complete Guide: movement, references, dial code, catalog dates.
- Adventures in Amateur Watch Fettling, A Seiko 6217-8001 from April 1967: production dates and faults.
- Ikigai Watches, Collector’s guide to the 62MAS, and The Watch Bloke, Seiko 6217-8000: crowns, case backs, replaced parts.
- Fratello, Seiko 62MAS vs the SLA017, and WorldTempus, Dive attraction: the name.
- Plus9Time, 62MAS Original Tropic Strap.
FAQ
When was the Seiko 62MAS released?
In 1965. The small-crown 6217-8000 went into production in April 1965 and was made for two or three months; the big-crown 6217-8001 took over from July 1965 and ran until early 1968, when the 6105-8000 replaced it.
Why is it called 62MAS?
62 comes from the first two digits of its 6217 caliber, and MAS stands for automatic self-dater, an automatic with a date. Fratello and WorldTempus both give this reading. 62MAS was also the watch's code in Seiko's Japanese catalog.
What is the difference between the 6217-8000 and the 6217-8001?
The crown. The 8000 has a small crown and was only made for a few months in 1965; the 8001 has a larger crown, a longer crown tube and a matching recess in the case side. Both use the 6217A movement and both carry dial code 6217-8000T.
Does the Seiko 62MAS hack or hand-wind?
Neither. The 6217A is a 17-jewel automatic beating at 18,000 vibrations per hour, with a date and quickset, but no seconds stop and no hand-winding (The Seiko Guy).
How much does a vintage Seiko 62MAS cost?
It depends on the crown version, originality and condition. Our sampled sold ranges appear on this page after our first sampling in November 2026. They cover original 6217s only, not the modern re-creations or 62MAS-style mods.
Is the Seiko SPB143 a 62MAS reissue?
Seiko calls the SPB143 a modern re-interpretation of the 1965 diver, not a re-creation. The faithful re-creations are the SLA017 of 2017 and the SJE093 of 2023. The SPB143 has been replaced by the SPB451 and SPB453.