Seiko’s Limited Edition Marinemaster Professional is a Chunky $7,200 Rolex Sea-Dweller Alternative

With a new calibre 8L45 movement (+10 to -5 seconds per day), one-piece titanium case construction, 600 metres of water resistance, and an L-shaped gasket to prevent helium infiltration and eliminate the need for an escape valve, the Seiko Marinemaster 60th Anniversary Limited Edition (ref. SLA081J) is technically the most impressive release of Seiko’s new Prospex line-up.

Yes, the entry price of AUD$7,200 is a tough one to stomach for fans of the brand who are traditionally accustomed to sub-$1000 watches, but this is a serious watch that commands a serious price.

To find a competitor to this watch, at least on paper, you have to look far up the price bracket. The Tudor Pelagos FXD, Citizen Promaster Dive Super Titanium, and Omega Seamaster Diver 300M are some of the better-looking alternatives but they can’t stand up to the Seiko Marinemaster 60th Anniversary Limited Edition (ref. SLA081J) when it comes to the numbers. If you want something that balances aesthetics with performance, there’s the Oris Prodiver GMT and Delma Blue Shark II. However, the legendary Rolex Sea-Dweller (AUD$21,700) is the closest to the Marinemaster, which says a lot about just how impressive this new Seiko is.

Key Specifications:

• Movement: Calibre 8L45 automatic
• Power reserve: 72 hours, with an accuracy range of +10 to -5 seconds per day
• Case: Titanium with super-hard coating
• Case diameter: 45.4mm
• Case thickness: 16.0mm
• Water resistance: 600m, designed for saturation diving
• Dial: Blue gradient dial, textured surface, thick clear paint for added depth
• Bezel: Diamond-like carbon (DLC) coated stainless steel for superior scratch resistance

Powered by a new calibre 8L45 automatic movement, the Seiko Marinemaster 60th Anniversary Limited Edition (ref. SLA081J) boasts a power reserve of 72 hours and an accuracy range of +10 to -5 seconds per day. This is close to the Rolex Sea-Dweller (ref. 126600) which uses a calibre 3235 movement that offers 70 hours of power reserve and precision of -2/+2 seconds per day. Clearly, Seiko is not messing around with the specifications of this model.

Of course, the Rolex Sea-Dweller sets a high bar with water resistance of 1,220 metres / 4,000 feet, and that’s not even scratching the surface of the Rolex Deepsea Challenge’s 11,000 metres (36,090 feet). Still, for a watch like the Seiko Marinemaster to offer 600 metres of water resistance is impressive nonetheless. It achieves this with a special L-shaped helium-resistant gasket that eliminates the need for an escape valve.

Construction-wise, the case of the Marinemaster is made out of titanium with a super-hard coating, while the stainless-steel bezel insert has a diamond-like carbon coating to achieve a surface hardness approximately six times greater than it would be otherwise.

The dial is inspired by Shinkai or “the deep sea,” and features a new textured pattern with thick, clear paint to form a beautiful lustre in natural light. Impressively, the indexes are formed as part of the dial through a moulding process and the word “PROFESSIONAL” has been inscribed to round out a surprisingly versatile design.

Comfort is achieved with a bracelet that features rounded links for a smoother, more comfortable fit on your wrist.

Limited to 600 pieces, the Seiko Marinemaster 60th Anniversary Limited Edition is priced at AUD$7,200 and is available from July 2025 at Seiko Boutiques and select retailers worldwide.