Instead of using a conventional helium escape valve, Seiko turned to their proprietary L-shaped glass seal. The final 51-mm watch is water-resistant to 600 m (60 bar, 1,969 ft) and suitable for saturation diving.
However, there are also watches with high-quality quartz, kinetic, or Spring Drive movements. Seiko equips most models with stripped-down Grand Seiko calibers. While some titanium versions can survive up to 100 bar (1,000 m, 3,280 ft), the stainless steel editions are water-resistant to a maximum of 20 bar (200 m, 656 ft). These editions tend to have lower water resistances. Only a few of the more affordable models are made of stainless steel and, in some instances, have a plastic outer case. Seiko has been crafting these timepieces out of titanium since the very first model, known as the Grandfather Tuna. The wearer can operate the bezel via openings on either side of the outer case, which expose a section of the bezel's toothed edge.
It reaches up past the unidirectional diving bezel and protects the bezel and case against strong impacts. Some collectors lovingly refer to these timepieces as "hockey pucks" since most have black cases and are up to 52 mm in diameter.Įvery Tuna model has a large outer case that is attached to the actual case by four screws. Instead, this moniker comes from Seiko's fan community, who recognized the resemblance between this watch's distinctive outer case and a can of tuna. Of course, "Tuna" is not this timepiece's official name.
#FLUID BROWSER VS HELOIM PROFESSIONAL#
The Seiko Tuna is a series of professional diving watches that have been in production since 1975.