The first professional divers watch from SEIKO was released in 1968. It was the 300m, HI-BEAT (10Hz), 6159-700x which was the result of improvements made to Seikos first ever diver in 1965, the 6217-800x, and to the 6215-700x from 1967. Seiko had received complaints from people really using the watches in tough environments, like e.g. oil-rig personell. The end result, the grand father Tuna, 6159-701x, saw the day of light after seven more years of development in 1975. Ever since Seiko has been known for its well proven divers watches.
If you want a diver with the Grand Seiko name on it you could, so far, choose between four different models. The Spring Drive equipped SBGA029 and 031 (released in 2008) or the quartz based SBGX115 and 117 from 2014. All four are air divers with a depth specification of just 200m.
At Baselworld 2017 Seiko showed something that many fans have been wanting for a long time; a professional Grand Seiko diver with a mechanical movement. And they didn’t just use any plain 28.800 bph one, no they put the HI-BEAT 9S85 caliber in. The only other divers from Seiko using a HI-BEAT movement since the 6159 from the late 60s and mid 70s are the brutal SBEX001, 003 and 005 with the 8L55.
Available from August 2017 are two versions; the SBGH255 (black dial) and limited edition (500pcs) blue dialed SBGH257.
Accuracy: -3 to +5 seconds per day
Power reserve: 55 hours
High-intensity titanium case and bracelet
Sapphire crystal with AR on the inside
600m water resistance
46.9mm x 17mm (diameter x thickness)
The watch is big (though quite a bit smaller than the SBEXs), but sits very comfortable on the wrist (mine is 19cm). The low weight due the use of titanium is helping a lot and Seiko really knows how to create a case that sits well.
This is unmistakingly a (Grand) Seiko diver. You can clearly recognise the heritage from the ancestors but it feels very modern with the many sharp, Zaratsu polished edges and surfaces. The case does not need a helium valve as it is using the Seikos innovative L-shaped gasket. The dial is made of iron to protect the movement from magnetism (16.000 A/m).
If you opt for the limited edition SBGH257 you also get an extra-strength blue silicon strap along with the bracelet.
Prices: SBGH255, 12.100€ and SBGH257, 12.300€