The “Yellowfin Tuna” is one of Seiko’s highlights for the last quarter of 2018. Officially called the Prospex Diver’s Watch Limited Edition SRPD14K1, this timepiece sits at the confluence of two iconic Seiko lines: the Tuna and the Prospex.

Seiko Prospex Diver’s Watch Limited Edition SRPD14K1 Yellofin Tuna

The Tuna is one of Seiko’s icons, which has remained a well-kept insider’s secret among aficionados for the better part of four decades. This series started in 1975 with the release of ref. 6159-7010 that fans have affectionately dubbed the “Grandfather Tuna”. The watch was a solution to a specific problem – Seiko had received a letter from a professional diver, who detailed how his watch’s crystal had popped out during the decompression phase in saturation diving. The prevailing solution then was to equip diver’s watches with a helium escape valve to, as its name suggests, allow the helium gas that had built up inside the watch during saturation diving to escape. Seiko, however, approached the problem from an entirely different perspective: by preventing any helium gas from entering the watch in the first place.

The Tuna was designed to accomplish this. By using a special L-shaped gasket, as well as a monocoque case with an external shroud, the “Grandfather Tuna” was impervious to helium gas, thus nipping the problem in the bud. Its case design was form following function in its purest sense, and would largely remain unchanged in subsequent models. Of course, the model’s resemblance to a can of tuna was not lost on collectors, who dubbed it the Tuna for this very reason.

Seiko Prospex Diver’s Watch Limited Edition SRPD14K1 Yellowfin Tuna

The Prospex, on the other hand, is less a specific design or model, and more a family of watches with a common thread running through them: timepieces built to PROfessional SPECificationS. Unsurprisingly, most Prospex timepieces are/have been diver’s watches, although travel-themed worldtimers and pilot chronographs have also been offered in the past.

The “Yellowfin Tuna” is a bona fide dive watch, and part of Seiko’s steps to democratise the Tuna family for a wider range of wearers. The dead giveaway here is its size; at 43 millimetres, it’s part of a line of “Baby Tunas” that are far smaller than the original’s 50-millimetre case. It’s water-resistant to 200 metres instead of 1,000 metres like the MarineMaster line of Tuna timepieces, which has allowed Seiko to maintain a more accessible price (SG$775.80). Don’t be mistaken though – this is a well-built Prospex with all the necessary appointments, and not an entry level Seiko.

Seiko Prospex Diver’s Watch Limited Edition SRPD14K1 Yellofin Tuna

In terms of design, the “Yellowfin Tuna” sports a yellow brass shroud that, together with the white bezel markings, are reminiscent of yellowfin tuna in the ocean. At the same time, its dial and bezel hark back to Seiko’s wildly popular “Monster” series of diver’s watches. The bold lines and colours here will appeal widely to wearers who aren’t just looking for legibility, but also a strong design that has withstood the test of time. Powering the watch is a Seiko staple, the self-winding 4R36 calibre.

The “Yellowfin Tuna” comes in a limited run of 2,200 pieces, and is only available in Singapore, Malaysia, Hong Kong, Brunei, and Macau. Visit for more information, find out where to buy one at, and follow the brand on Instagram @SeikoSG.

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Prove the depths with Seiko’s “Yellowfin Tuna” Prospex Diver

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