Seiko makes some very nice, affordable watches in the Seiko 5 range, but until now, if you wanted a GMT, you had to pay for their higher-priced Presage line. Soon, that will change. Here’s what we know about the new, SSK, an SKX-style dive watch with GMT movement.

Take the classic SKX case. It’s been discontinued as an excellent affordable beater watch. Its replacement is the SRPD model. Even Seiko knows better than to call them SPRD; on their Web site, they call them SKX style.

If you wanted a GMT Seiko, you’d have to get the SPB221 or similar, a GMT with date as a subdial, and a power reserve indicator. The dials are highly geometric, and the case is on the large side at 42.2mm, and a long 49.2 lug to lug. It doesn’t quite fit the bill, if you want a nice, affordable GMT that won’t cost $1400 USD.

So knowing that, what’s coming? What should you be interested in and waiting for with bated breath?

The SSK001K1 in black, SSK003K1 in blue, or the SSK005K1 in orange. The watches are still going to be 42.5mm and a comfortable 46mm lug to lug, the traditional SKX case size, but you get the date window at 3 instead of a subdial at 6.

A word on GMT movements

There are two types of GMT movements, in general. They are the “caller” and the “traveler” GMT. The big difference is in how the 24h hand sets, how the hour hand sets, and the effect on how you use them.

Caller GMT

This is a GMT movement where you set the hour and minutes normally. The hour adjusts with the minute hand on the second position of the crown. The first position sets the date, and when you rotate the crown in the opposite direction, it sets the 24h hand. The hand only advances, so if you miss the hour, you go all the way around again. The 24h hand sets independently of the hours and minutes, so when you travel, you keep the watch set at home time, and adjust the 24h hand for travel time.

Traveler GMT

The “traveler” GMT movement works differently. The Presage SPB221 uses a traveler movement. The Grand Seiko SBGN001 uses a traveler movement. Here, the 24h hand and minute hand set together on the 2nd position of the crown. The hour hand sets independently on position 1, and it sets both forwards and backwards. This is incredibly convenient while traveling. You set the home time with the 24h hand, and when you land somewhere, adjust the hour hand to the local hour, keeping minutes the same.

I had strongly hoped that the 4R34 would be like the 6R64, with a normal date window at 3, but without the power reserve and subdial. I was wrong. Here’s how we know. The manual for the 4R34 is at seiko’s Web site.

This is most likely accomplished by taking an NH35 movement and converting the DAY parts to the 24H parts. If you didn’t have the DAY corrector part, the DAY wheel would rotate through 24 hours throughout the day. Removing that part and converting the wheel to a hand makes it possible to achieve a GMT movement without much change.

Nevermind. A GMT Seiko 5 SKX is awesome and opens up a lot of possibilities for very cool affordable GMTs in the future. Expect the Seiko SKX style GMT to be about $500 USD more or less. As soon as we have official info, we’ll share it.