Prospex for Seiko basically means "Professional Specification" that their timepieces in this category  are built with very high standards to be used by professionals. One that stands out to collectors around the world and known for one of a great value for money Japanese Domestic Model(JDM), is the scuba diver series; SBDC0313nicknamed by the Seiko community as "Sumo".

Blue Sumo Ref. SBDC033

The Seiko Prospex 200M Automatic Sumo Ref. SBDC033 was initally released in 2007 under the reference. SBDC003, but now with a few changes made on the latter. The overall look of the Sumo is one of a kind, quirky, but still serious like a professional dive watch. Powered by Seiko's automatic caliber, 6R15, operating at 21,600 BPH (3 Hertzs) with hacking and hand winding capabilities. It has 23 jewels with a power reserve of 50 hours through a Spron 510 mainspring.

Lovely Blue Dial

The 200m water resistant stainless steel case measure 45mm case without the crown, and has a lug to lug length of 52.6mm, and a height of about 12.9mm, with a lug width of 20mm. The bezel is aluminum and has large printed markings on it. It rotates buttery smooth into 120 positions has zero free play in a clockwise direction. Mixture of satin brush and Seiko high polishing on the sides can be seen on the whole watch, making the Sumo feels a notch higher than other dive watches in the same price point. Similar to the JDM models, the screw down crown at four o'clock is signed with an "S". Moving to the back of the watch, the screw down case back allows 200m water resistant , and is also brushed, featuring the recognizable tsunami emblem that is staple on the other Seiko divers. The case does comes with lug holes allowing swapping of straps with ease.

Seiko's LumiBrite shines like a torch

The watch's unique aesthetic along with the fat markers on the bezel, now the knickname of "Sumo" starts to ring a bell. The hour markers and hands are both generously coated with Seiko's LumiBrite allowing it to glow brightly in the dark for hours.

The design of the steel bracelet compliments the watch beautifully, with a seemless look and feel. The Sumo is is quite a worthy contender in it's price range.