The Seiko-Tuna Collector's Guide

Seiko Tuna is the brand name of a line of watches designed to be used by professionals and for scuba diving. The watches were created by Seiko with increased depth and saturation in mind. The watches of the seiko tuna mod-range) are secured with the screw-on shrouds. They have earned them the name "Tuna".

The Seiko Tuna range boasts of many firsts. It was the first to include a ceramic-coated titanium shroud, a titanium monocoque case, an L-shaped gasket, and a vented rubber strap. Seiko Tuna watches Seiko Tuna watches are designed for practicality and can be used as professional divers' instruments at great depths.

The History of The Seiko Tuna

In 1975, the first seiko tuna watch was created in response to a request that the company received in the year 1968. Seiko divers watches have been made since 1965. A Japanese saturation diver, Kure City, had complained about Seiko divers watches. These pre-Seiko Tuna models weren't sturdy enough to stand up to impacts and were not built to withstand prolonged exposure to high underwater pressure.

Divers watches must withstand uniquely difficult conditions. Professional divers breathe helium with oxygen at extremely deep depths where helium gets easily absorbed by a watch's rubber seals. Divers undergo the necessary decompression. The seals on the watch release helium through specially designed escape valves. Without these escape valves, the watch would fail to function properly. You can buy seiko tuna for sale.

Details and Specifications

Movements

The Seiko Tuna can be divided into four parts including 6159B and 7C46. 5M23A and 7C46. The movements were developed in-house.

Suwa, the division of the company's Suwa Division, has created the 6159B operation that operates the Grandfather Tuna as well as the 7549A movement for the first Golden Tuna.

The 6159B movement, which was taken from the renowned movement 61xx, which was used in the Grand Seiko, was confined to professional Seiko dive watches and was never utilized for any other Seiko model.

It's unclear exactly who made the 7C46 and 5M23A movements of the reissued Golden Tuna and the Baby Tuna however it is probably Suwa also.

At 25 jewels the 6159B movement features the most functional jewels of the entire range. On the other hand, the 7549A movement has the least number of jewels. The 7C46 and 5M23A follow closely at seven jewels and six jewels, respectively. All watches in the range are able to be wound manually. They typically cost 36,000 bph.

DIALS

Black dials and LumiBrite luminescence are the mainstays of the seiko tuna mod collection. The watches are also known to feature markers instead of numbers to mark the hours. An upside-down triangle represents the 12-o'clock position, while circle-shaped dots or dots indicate all other hours.

All Seiko Tuna watches have "Seiko" written on their dials, as well as the indication of depth. The dial of the 6159 7010 Seiko Tuna watch indicated the depth as 600m rather than 600m. This was later rectified by 6159-7001 models in 1975, and the 6159-70719 model in 1976. Some people do not agree, citing models that displayed "600m" as an indication of depth.

BEZEL

All watches in the Seiko Tuna series feature a uniform, unidirectional rotating bezel. It informs divers of how long they've been submerged and the time it has taken to reach there. Each spin takes about half an hour. A click is one click. There are two entry places on the shroud to spin the bezel. Once it is set, divers must look at the time that the hand marks to calculate the time elapsed.