Seiko Remembers Legendary Japanese Explorer with Prospex 6105 Remakes

The SLA049 and SLA051 "Naomi Uemura".

Legendary for being the first man to reach the North Pole solo, Naomi Uemura (1941-1984) was an explorer who notched up several expeditionary feats before disappearing in 1984. Amongst his achievements was a solo, sled-dog run from Greenland to Alaska in 1976 – a two-year, 12,500 km journey – in preparation for climbing Vinson Massif, Antarctica’s highest peak. It was on this trip that Uemura wore a Seiko ref. 6105, the “turtle” diver launched in 1970 that has since become one of Seiko’s best known dive watches thanks to the distinctive case shape.

Uemura disappeared in winter 1984 whilst descending the Denali – after successfully reaching the peak – never to be seen again. February 2020 would be his 80th birthday had he lived. To commemorate his life, Seiko has introduced the Prospex The 1970’s Diver’s Modern Re-interpretation modelled on the ref. 6105 worn by Uemura and available in two variants, the limited-edition SLA049 and the regular-production SLA051.

The Seiko ref. 6105 of 1970 worn by Uemura during his 1976 solo sled-dog run

Initial thoughts

Seiko loves limited editions – a trio of Prospex models for its 140th anniversary was just announced – and the limited editions are often facelifts of existing models. To an extent, that remains true. The new SLA049 looks very similar to the SPB183 – nicknamed the “Captain Willard” by enthusiasts after the character who wore on in Apocalypse Now – that was released late last year. Like the SLA049, the SPB183 was a limited edition inspired by the ref. 6105.

However, there are several crucial differences. The new SLA049 has a blue dial textured to resemble the mountainous terrain that defined Uemura’s career. More importantly, the SLA049 is powered by Seiko’s top-of-the-line 8L35 calibre, whereas the earlier 6105 re-issues were powered by the 6R35. Lastly, the date window has been moved from its conventional three o’clock position to between four and five o’clock – a change that will no doubt be controversial.

The SLA049

Nevertheless, I do genuinely enjoy the story behind the SLA049. I’d never heard of Uemura before the launch of this watch, but now I am in awe of what he achieved in his short lifetime.

And while Seiko is often lambasted for releasing many limited editions that are too similar, this is one that makes a lot of sense. This resonates more with me, and I am sure with many others as well, simply because Uemura was a real-life hero. The SPB183 “Captain Willard”, on the other hand, was inspired by a fictional character.

That being said, the greatest sticking point for most would be the high price. With a retailer price of US$3,100, the SLA049 is twice as expensive as the similar-looking SPB183. The price still puts it within the ballpark for watches powered by the 8L35, which makes the price fair for the movement but high relative to the design.

The line-up also includes the standard-production SLA051 that has a slightly lower price of US$2,900. It’s cheaper but not by much, so but unless you’re specifically after its monochromatic look, the limited-edition SLA049 makes way more sense.

The standard-production SLA051

Commemorating Naomi Uemura

Although inspired by the 1970s original, the SLA049 is contemporary in its execution. Its dial is finished with a granular texture evocative of the landscapes that were no doubt familiar to Uemura. The date window is now wedged between the four and five o’clock markers, likely done to satisfy the revised ISO standards for a diver’s watch that require luminous plots for all hour markers. The rest of the dial remains virtually identical to that of the limited-edition SPB183 “Captain Willard”.

The standard-production SLA051 shares the same granular dial texture, but in charcoal grey, giving it a greater resemblance to the vintage ref. 6105.


Both the SLA049 and SLA051 use the same “turtle” case characterised by a cushion shape and a bulge at five o’clock for the crown guards. The cases have a satin-brushed finish, with polished lines running along the flanks.

The movement is the 8L35, essentially a simpler version of the Grand Seiko 9S55. The movement beats at 28,800 vibrations per hour, and has a 50-hour power reserve.

Key facts and price

Seiko Prospex The 1970’s Diver’s Modern Re-interpretation
Ref. SLA049 (SBDX045 in Japan)
Ref. SLA051 (SBDX047 in Japan)

Diameter: 44 mm
Height: 13 mm
Material: Steel
Crystal: Sapphire
Water resistance: 200 m

Movement: 8L35
Functions: Hours, minutes, seconds, and date
Winding: Self-winding
Frequency: 28,800 beats per hour (4 Hz)
Power reserve: 50 hours

Strap: Steel bracelet, with an additional silicone strap for the SLA049

Limited edition: 1,200 pieces for SLA049
Availability: At Seiko Boutiques and selected retailers from July 2021 onwards
Price: US$3100 (SLA049); US$2900 (SLA051)


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