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Seiko Prospex Professional Tuna Review: Unparalleled Allure

Seiko Prospex Professional Tuna Review: Unparalleled Allure

Presented in a bulky case design, the watch still wears comfortably on your wrist. Explore Seiko Prospex Professional Tuna here!
May 16, 2024

Among many options for Seiko watches, the Seiko Prospex Professional Tuna stands as one of the prominent forefronts. Simply known as Seiko Tuna, this model is presented as a symbol of resilience, precision, and design. Tuna is a form of the brand’s commitment to accuracy, innovation, and durability.

The bulky design might be your first impression upon seeing this Seiko dive watch. No wonder this Seiko dive watch has garnered admiration from diving enthusiasts and watch aficionados alike. It caters to both professional and adventurous horology enthusiasts.

In this Seiko Tuna review, we delve deep into the features, design, performance, and legacy of the Seiko Prospex Professional Tuna.

A Unique Design Inspired by a Tuna Can


The Seiko Prospex Professional Tuna, often referred to simply as the “Tuna,” has a fascinating history that traces back to the early 1970s. It was designed to tackle the challenges faced by saturation divers, who needed a timepiece that could withstand the extreme pressures and conditions of deep-sea exploration. 

The initial Tuna, with its distinctive shrouded case, was a game-changer. The shroud not only protected the watch from impacts but also ensured water resistance, making it a reliable companion for divers. But who can expect that the case design is inspired by a tuna can.

A bulky case of Seiko Prospex Professional Tuna which flaunts durability
A bulky case of Seiko Prospex Professional Tuna which flaunts durability

The Seiko Tuna’s design is instantly recognizable, characterized by its unconventional shrouded case, resembling a tuna can, which provides added protection against external forces and enhances water resistance

This distinctive feature not only gives the watch its name but also sets it apart from conventional dive watch designs. The shroud is made of a combination of stainless steel and a hardened material, creating a tough exterior that can withstand the rigors of deep-sea exploration.

Over the years, Seiko has continuously refined Tuna’s design and technology, incorporating cutting-edge features while preserving its iconic silhouette. The Tuna’s ability to endure the harshest environments has earned it a place of honor among professionals and collectors alike.

Read also: On-Hands: Seiko Prospex PADI “Great Blue” Sumo Review

Seiko Prospex Professional Tuna Review

With its distinctive shape, robust construction, and history rooted in the needs of professional divers, the Seiko Prospex Profesional Tuna has a lot to unpack. In the next Seiko Tuna review, we’ll take a look at each feature and what it offers. 

We have two Seiko Tuna available in our store, the Prospex Professional 1000M Tuna Ref. SBBN047 and Prospex Professional 1000M Tuna 35th Anniversary Blue Ref. SBBN051 – Ltd Ed 1200pcs. Each carries a similar performance with a different appeal on the dial.

Movement Caliber 7C46. Seiko 7-Jewel Hi-Tech quartz.
Case Titanium case with super-hard coating and ceramics
Diameter 49.4mm
Lug to lug 49.4mm
Lug width 22mm
Thickness 16.3mm
Water resistance 1000m (ISO certified)
Specifications of Seiko Prospex Professional 1000M Tuna Ref. SBBN047

Watch Case

The most notable aspect of Tuna’s case is its shrouded design, often likened to a tuna can due to its rugged exterior. This shroud serves as an outer protective layer, encasing the watch’s inner components and offering heightened resistance to external elements. 

Made from a combination of titanium and Seiko’s proprietary hardened material, the shroud provides a formidable barrier against impacts, scratches, and the effects of pressure underwater. As for the crown, Seiko puts this significant part at 4 o’clock. This placement reduces the risk of the crown accidentally digging into the wrist and enhances comfort during dives. 

A monobloc design that makes the case of Seiko Prospex Professional Tuna unique
A monobloc design that makes the case of Seiko Prospex Professional Tuna unique

Measured 49.4mm in diameter, the watch does wear big – but it’s not a nightmare to have it on the wrist as it is made of titanium. Moreover, thanks to its monobloc design, the watch can handle water resistance at an impressive 1000m (ISO Certified). 

The Seiko Prospex Professional Tuna is not a small watch by any means, and its dimensions reflect its purpose as a rugged tool watch. While its size might be imposing, its ergonomic design and integrated straps or bracelets contribute to a comfortable fit on the wrist. 

The shrouded case’s unique shape adds to the watch’s wearing comfort, as it molds around the wrist and reduces potential snagging on the equipment during dives. Undoubtedly, this Seiko dive watch would undoubtedly project a strong and masculine presence when worn on the wrist.

To top it off, this Seiko dive watch Tuna also comes with a ceramic bezel insert. The outer case also protects this 120-click bezel from unintentional rotation and shock to the case during diving operations. 

Watch Dial

Moving on to the dial for another highlight of Seiko Prospex Professional Tuna, it makes an impressive result. The dial flaunts a nice combination of a timepiece that is not only reliable in demanding environments but also visually appealing.

Large markers with contrasting colors to ensure legibility
Large markers with contrasting colors to ensure legibility

The dial of the Seiko Tuna is designed with the utmost legibility in mind. It features large, bold hour markers and hands, often coated with Seiko’s proprietary Lumibrite luminescent material. 

A well-applied Seiko LumiBrite on hour markers, watch hands, and inner ring to ensure legibility in dark environments
A well-applied Seiko LumiBrite on hour markers, watch hands, and inner ring to ensure legibility in dark environments

This luminous material ensures that the watch remains highly readable even in low-light conditions, which is essential for divers exploring the depths of the ocean. The high contrast between the markers and the dial background aids quick and accurate time reading, a crucial factor in underwater scenarios.

As part of Seiko’s division of professional sports watches, the dial bears the Prospex logo in the form of an “X” at the 6 o’clock mark. Safeguarding the dial is a sapphire crystal with an anti-reflective coating, providing exceptional resistance against scratches.

Read also: Seiko Open Heart Dial Watches: When Beauty Meets Mechanics

Reliable Watch Movement

Powering the Seiko Tuna is the renowned Seiko automatic movement, known for its reliability and accuracy. The caliber used varies depending on the model, with some featuring the time-tested Seiko Caliber 7C46 quartz movement, prized for its robustness and long battery life. 

Until these days, the Seiko Caliber 7C46 is considered the most reliable and robust movement ever produced. It comes with low-drain electronic circuits which gives a significant effect on the stepper drive system, resulting in an incredibly high torque. Linked to a 7 jewel gear train, the movement flaunts an impressive battery life of 5 years. Further, it still has another impressive thing to unfold.

The Seiko Caliber 7C46 features a dual-rate trimming mechanism, enabling synchronization for enhanced precision. Additionally, it includes an ‘end of life’ signal, wherein the second-hand advances in two-second intervals while maintaining impeccable accuracy. While such a characteristic is now standard, it was truly revolutionary in its earlier days. 

The automatic versions, on the other hand, are equipped with movements like the Caliber 8L35, which offers a 50-hour power reserve and is designed to withstand the challenges of deep-sea diving.

Strap Options

Seiko offers different variations of the strap to cater to diverse preferences and uses. Some models of the Seiko Tuna come with a traditional rubber strap, while others may feature a hybrid strap that combines silicone rubber with fabric or other materials.

For example, the SBBN047 and SBBN051 come with Seiko’s black silicone strap which is a great suit for diving. The strap boasts impressive robustness and resilience against damage. Not to mention the seamless design that tapers down to its tips avoids the watch from appearing excessively bulky.

Final Thought

In the world of dive watches, the Seiko Prospex Professional Tuna remains an enduring icon that embodies the spirit of exploration and adventure. Its unique design, exceptional water resistance, and reliable movement make it a favored companion for both professional divers and watch aficionados. 

With a history deeply rooted in the demands of the deep sea, the Seiko Tuna continues to stand as a testament to Seiko’s commitment to excellence in watchmaking. 

Read also: 6 Picks of Seiko Automatic Divers Watch for Marine Adventure

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