Head-To-Head: Seiko Gundam 40th Anniversary Limited Editions Prospex 1000m Marinemaster Professional Zaku II SLA029J1/SBDX027 versus Seiko Marinemaster Professional 1000m Automatic Diver SBDX011

In my collection I have the Seiko Emperor Tuna SBDX011 and more recently, the Seiko Gundam Tuna Zaku II SBDX027 (or SLA029J1 to the global market). Both are similar in most areas but there are subtle differences. Apart from some cosmetic changes to represent the tie-in to the Gundam lore, the changes can be found mostly on the watch casing design itself.





Below is the table of specifications for both watches. As you can see in the table below, size-wise, there are slight differences.

Specifications	SLA029J1/SBDX027	SBDX011
Movement	8L35 (running at 28,800 BPH)	8L35 (running at 28,800 BPH)
Strap	Silicone	Rubber
Dial	Green	Black
Diameter	52.4 mm	50 mm
Lug width	22 mm	22 mm
Lug-to-lug	53.5 mm	52 mm
Thickness	17.2 mm	17.4 mm
Weight	165 gm	147 gm
Crystal	Sapphire	Sapphire
Casing	Titanium + Diashield	Titanium + DLC
Shroud	Ceramic	Ceramic
Bezel Inlay	Sapphire with partial lume scale	Titanium with lume pip
Water Rating	1,000 meters	1,000 meters
Manufacture	Limited edition, Made in Japan	JDM
MSRP	YEN400,000	YEN300,000

For the SLA029J1/SBDX027, based on what I can see, Seiko must have added a sapphire insert to the bezel. This enabled the designers to add the Lumibrite luminous paint on the surface of the titanium bezel and have a protective layer of sapphire over it. See the comparative photos below.

SLA029J1/SBDX027

SBDX011

For the SLA029J1/SBDX027, the new shape of the hands, the re-introduction of the hour marker for 3 o'clock and the re-location of the date window makes for a cleaner and more symmetrical dial placement when compared to the original SBDX011.

SLA029J1/SBDX027(L) SBDX011(R)

SLA029J1/SBDX027(L) SBDX011(R)

The strap material has changed from rubber to silicone. Design remains the same but the silicone version wins hands-down on softness and durability.

SLA029J1/SBDX027(L) SBDX011(R)

Additional changes can be found on the shape of the buckle. The SLA029J1/SBDX027 version has an addition flare with enough space to have it signed with the brand's name unlike the SBDX011 version.

SLA029J1/SBDX027(T) SBDX011(B)

Both watch are thick with no obvious visual differences apart from a few notations cut into the ceramic shroud.

Overall

I consider myself as a relatively conservative person when it comes to styling. Both watches are huge and attention grabbers. Nevertheless, the green is more eye-catching. If you are not into showing off, the SBDX011 is the watch for you, otherwise, go for the SLA029J1/SBDX027.

I personally would go for the SLA029J1/SBDX027.


Photo Gallery