The Old SZSC004 & New SPB103J1 Seiko Green 'Hulk' Sumo

20mm Angus-J Louis 316L Stainless Steel Watch Bracelet for Seiko Sumo SBDC001, Brushed/Polished, V-Clasp SS201820B057

One of Seiko’s most popular divers watch ever produced was the Seiko Prospex 200M Automatic Seiko Sumo Ref. Sbdc001, which was initially released back in 2007. The green hulk is powered by a automatic caliber, 6R15, operating at 21,600 BPH (3 Hertz), with hacking and hand winding capabilities. It has 23 jewels with a power reserve of 50 hours.

20mm Crafter Blue – Military Green Rubber Curved Lug Watch Band for Seiko Sumo SBDC001 CB02I-20A20BZZRU

After twelve long years, Seiko have finally came out with a new “Green Sumo”, Ref. SPB103J1. The 2019 new green sumo was the talk of the town after it was introduced earlier at Bezelworld 2019. The new Sumo was introduced with a few upgrade which caught everyone’s attention.

20mm Endmill watch band for SEIKO Sumo SBDC001, SBDC003, SBDC005, SBDC031, SBDC033, V-Clasp SS201820B030

The green hulk is water-resistant to 200mm, which is considered a professional grade specification. The measurements of the watch case is 44mm, (without the crown), and has a lug to lug length of 51mm, and a height of 13mm, with a lug width of 20mm.

20mm Straight End Emerald Green FKM Rubber Quick Release Watch Band, Brushed FKM01I-20A18BIW01

One of the traits all Seiko Sumo watches share is the fat markers used on the bezel. For those who didn’t know where the nick name “Sumo”, came from, many have said it was because the marker at 12’o clock resembles the ‘Mawashi’, which is the underwear worn by Japanese sumo wrestlers during a match. Honestly, when I first looked at the 12 o’clock marker on the green hulk, I was thinking it looked more like an onigiri, “Japanese rice ball”, instead of a sumo wrestlers underwear.

Left: MiLTAT 20mm 3 Rings ZHAKA JB watch strap 3D woven nylon – Rustic Brown Camouflage, Brushed 20A20BZZ00N4S12
Right: 22mm 5 Ring ZHAKA JB Military Watch Strap Ballistic Nylon Armband, Brushed – Black & Military 20A20BZZ00N4S10

There are a few upgrades with the new SPB103J1 that are worth mentioning. The new 2019 Seiko SPB103J1 feature the all new calibre 6R35. The base remains the same, with a 3Hz frequency, a central rotor for the automatic winding, a quick-set date, and a stop-second device, however, the power reserve has been improved to a comfortable 70 hours (instead of 50 hours).

20A20EBU59N7P49

20B20EBU59N7F18

Another upgrade that is worth mentioning for the new SPB103J1 is the glass material used on its predecessor has been finally upgraded from hardlex crystal to sapphire crystal.

20mm Gunny X MT Dark Brown Handmade Quick Release Rivet Monster Bund Leather Strap 20F20BPV13C1C74

There’s really nothing to dislike about the two green Seiko model diver watches. To some, the retail price for the new SPB103J1 sumo may be a little out of their budget, but considering with the upgrade with the new movement and material used, its definitely worth to consider since this could be one of those watches where you can wear for a life time.

SZSC004 Specifications:

Automatic Movement
Made in Japan
Caliber No : 6R15
23 Jewels
Mechanical Self-Winding (with Manual Winding)
Stainless Steel Case
Hardlex Glass
Average Daily Rate +25 Seconds -15 Seconds
200m Water Resistance
50 Hours of Power Reserve
Screw Back
Rotating Bezel
Screw Lock Type Crown
Anti-Magnetic 4,800A/m

SPB103J1 Specifications:

Automatic Movement
Made in Japan
Caliber No: 6R35
24 Jewels
Automatic with manual winding mechanism
Stainless Steel case
Sapphire crystal
Daily difference + 25 seconds-15 seconds
200m water resistance
70 Hours of Power Reserve
Screw Back
Lumi Bright : Hands and indexes
Water resistance suitable for air diving
Magnetic reluctance : Magnetic resistance
H52.6mm x W45mm x D12.9mm
Max wrist size: 19cm

Left: 20mm Endmill watch band for SEIKO Sumo SBDC001, SBDC003, SBDC005, SBDC031, SBDC033, V-Clasp SS201820B030
Right: 20mm Angus-J Louis Watch Bracelet for Seiko Sumo SBDC001, Brushed/Polished, V-Clasp SS201820B057

While we are on the topic on Seiko Sumo, it seems that we can carry on with the sumo discussion can carry on since we’re just informed that the all new Seiko Prospex SBDC095 / SPB125 SUMO 200m Diver Limited Edition is making its way to our office this weekend.