Urban Tuna

Seiko releases new Prospex Street Series that’s inspired by the “Grandfather Tuna”

IT was quite a catch. In 1975 Seiko rocked the diver’s watch world with its introduction of the Professional 600M, a timepiece that held 20 patents, and which was the product of around seven years of development.

Holding the distinction of being the world’s first diver’s watch to have been encased in titanium, the Professional 600M, or the 6159-7010, earned for itself the moniker “tuna” due to its distinct, generously sized, lug-less housing — which was likened to a can of tuna. Of course, this was the result of form following function; the case was shaped as it was because it was fashioned from a single block of titanium, which was then wrapped in a screwed-on, ceramic-coated titanium shroud. Further sealing the watch’s movement from the outside world was a collection of gaskets, among which is an L-shaped one. Its crystal was secured in place by a screw-down locking ring. All this allowed the watch its saturation-level 600-meter diving rating without having to resort to using a helium escape valve. It does not need one simply because the watch did not let any gases inside.

Now, while Seiko has spawned several other “tuna” models since 1975, the original rightfully owns the “Grandfather Tuna” title. And, needless to say, it’s quite a rich source from which to draw inspiration.

Which is exactly what the new Seiko Prospex Street Series has done.

The freshly released line is made up of three models; the SNE537P1 (which has a gray dial and bezel), SNE535P1 (in olive) and SNE533P1 (in navy). All three mimic the iconic protective case of the original, but which is now rendered in steel and hard plastic, and is smaller (at 46 millimeters), too.

Powering the Prospex Street Series is Seiko’s solar-assisted cal. V157, a quartz movement which uses light (not just sunlight) to recharge a battery that never needs to be replaced. When fully charged — three hours’ worth of exposure is usually enough — the watch can run for around 10 months without needing a recharge. It will be accurate to no more than 15 seconds faster in a month.

On top of this movement sits a dial adorned with a subtle camouflage pattern, and which features hands and markers coated in Seiko’s LumiBrite lume. Though the indices evoke those on the Grandfather Tuna, the hands do not, instead relying on those used in many current Prospex models. A date window takes the place of the 4 o’clock index.

Surrounding the dial is a uni-directional rotating bezel made from aluminum. Securing the watch to the wrist is a silicon strap with a faux leather pattern. Both the crown and caseback are screw-down affairs while Seiko’s Hardlex glass seals the watch on top. These latter touches allow the Prospex Street Series a respectable 200-meter water-resistance rating.

Clearly, that’s only a third of what the Grandfather Tuna was capable of. But Seiko is not pitching the Prospex Street Series as a hardcore diver’s piece. Rather, it says that the pieces’ light and reinforced cases, as well as silicon straps, make them perfect for daily use. In short, they’re excellent for the urban explorer.