Having launched a well received trio of Black Series dive watches in 2017, Seiko has done it again, but this time applying the black livery to more upscale models, including the Prospex Marinemaster and Prospex “Sumo”.

The flagship model of the new collection, the Seiko Prospex Marinemaster Black Series (ref. SLA035J1 or SBDX033) is all black with red accents on the dial, historically a common colour combination for dive watches.

According to Seiko, the choice of red was intentional, as it is the first colour to disappear underwater, starting from a depth of about 5 m or 15 ft. As a result, the seconds hand and depth rating disappear underwater, thus “[eliminating] unnecessary information allowing for instantaneous readability.”

Limited to just 600 pieces, the Marinemaster Black Series has a steel case with a black hard coating, and the bezel insert is scratch-resistant black ceramic. It’s powered by the 8L35, an automatic movement derived from the 9S55 used in Grand Seiko models, which means it has the same architecture but without the decorative finishing found on the Grand Seiko movement.

The other two Black Series models feature a black-and-orange colour scheme, and are more affordable. The first is the Seiko Prospex Black Series “Sumo” (ref. SPB125J1 or SBDC095), which is a rather large limited edition of 7,000 watches, no doubt because the Prospex Black Series “Turtle” of 2017 sold out swiftly.

The “Sumo” (left) and solar chronograph

The new Sumo has a steel case with a black hard coating, matched with an orange seconds hand and faux-vintage luminous hour markers. Inside is the automatic 6R335 movement.

Prospex Black Series “Sumo”

Identical in style is the Seiko Prospex Black Series Solar chronograph (ref. SSC761J1 or SBDL065), a solar-powered chronograph with a 24-hour hand that functions as a day or night display. Unlike most other Seiko dive watches this has no nickname, since enthusiasts and collectors usually only enthuse over Seiko’s mechanical dive watches.

Prospex Black Series Solar chronograph

Key facts and price

Seiko Prospex Marinemaster Black Series
Ref. SLA035J1 (SBDX033 in Japan)

Case diameter: 44.3 mm
Case height: 15.4 mm
Material: Stainless steel with black hard coating
Water resistance: 300 m

Movement: 8L35
Functions: Hours, minutes, seconds, and date
Frequency: 28,800 beats per hour, or 4 Hz
Winding: Automatic
Power reserve: 50 hours

Strap: Silicone strap

Limited edition: 600 pieces
Availability: At both retailers and boutiques from March 2020
Price: 300,000 Japanese yen

Seiko Prospex Black Series “Sumo”
Ref. SPB125J1 (SBDC095 in Japan)

Case diameter: 45 mm
Case height: 12.9 mm
Material: Stainless steel with black hard coating
Water resistance: 200 m

Movement: 6R35
Functions: Hours, minutes, seconds, and date
Frequency: 21,600 beats per hour, or 3.5 Hz
Winding: Automatic
Power reserve: 70 hours

Strap: Silicone strap

Limited edition: 7,000 pieces
Availability: At both retailers and boutiques from Feb 2020
Price: 90,000 Japanese yen

Seiko Prospex Black Series Solar chronograph
Ref. SSC761J1 (SBDL065 in Japan)

Case diameter: 44.5 mm
Case height: 13.7 mm
Material: Stainless steel with black hard coating
Water resistance: 200 m

Movement: V192
Functions: Time, date, and chronograph
Winding: Solar powered
Power reserve: 6 months on full charge

Strap: Silicone strap

Limited edition: 3,500 pieces
Availability: At both retailers and boutiques from Jan 2020
Price: 76,000 Japanese yen

For more, visit seikowatches.com.

Correction January 17, 2020: The cal. 6R35 runs at 21,600 bph, and not 28,800 bph as stated in earlier version of the article. 

Correction January 21, 2020: The 24-hour hand on the Solar Chronograph is a day and night indicator, and not an independently adjustable hand.