This Retro Dive Watch Revives the Original Wrist “Computer,” No Electricity Required

Slide rule bezels are arguably the most underrated watch feature. Although the technology is antiquated, like most watch features, it is unique, fun to play with and a great conversation starter.

The original “calculators” were common in mid-twentieth-century tool watches designed for pilots, sailors and engineers.

But the almost-lost tech is making a comeback in 2025 as interest in the novel look and joyously tactile function grows.

Ollech & Wajs

Ollech & Wajs was a highly respected tool watch brand during the height of slide rule bezels, with its tech widely used in the engineering and aerospace industries.

The Swiss watchmaker is paying tribute to that heritage by reviving the Selectron line.

Ollech & Wajs

The Selectron was marketed as a “computer” for the wrist during the Space Race, when the term was interchangeable with calculator.

It was notably supplied to General Electric aerospace engineers and test pilots during the 1960s.

A wrist “computer”

Slide rule bezels are simplified versions of standard slide rules, providing two logarithmic scales that assist in calculating complex equations on the fly.

Rather than overlapping cards or wooden panels, a bidirectional bezel corresponds with a dial track.

Ollech & Wajs

In this case, the P-104 Selectron is configured to calculate speed and distance in kilometers, a nod to the watch’s aerospace roots. With a little practice, it is surprisingly simple to use.

Founded in 1956, Ollech & Wajs specialized in slide rule bezels during the 1960s and 1970s. It provided different logarithmic scales geared toward dive watches, pilot watches and racing watches.

Ollech & Wajs

Although this watch is reviving the Selectron name, it is actually a rebranding of the newer P-104 design with an updated logarithmic scale bezel.

The heart of a dive watch

The Quartz Crisis of the early 1980s, along with advancements in pocket calculators, forced the brand to shut down.

However, it was resurrected in 2019 and launched with two new references, including the P-104.

Ollech & Wajs

The P-104 is loosely based on the Caribbean, one of the first Ollech & Wajs dive watch lines, introduced in 1964.

Later versions, like the Caribbean Oceangraph, featured complex bezel scales to calculate elapsed time.

Ollech & Wajs

High-performance divers are part of Ollech & Wajs’ prestigious history in the tool watch category. The company has offered watches with 1,000m water resistance. Even the ostensibly aeronautical-oriented P-104 Selectron boasts a 300m dive rating.

Under the hood, the new Selectron runs on a bespoke Soprod Newton Precision caliber P092 automatic movement, which has a date complication and a 40-hour power reserve.

Ollech & Wajs

Brands like Breitling and Citizen have kept slide rule bezels alive for decades, but Ollech & Wajs has an unmatched heritage in the niche horological space.

With the feature gaining popularity, the Selectron offers an interesting back story with an amusing and immersive experience.

Availability and pricing

The Ollech & Wajs P-104 Selectron will be available in May from Ollech & Wajs for $2,023. It comes on a black and orange “RAF issue” nylon NATO strap produced in the UK.

A steel beads-of-rice bracelet is available for an additional $313, and a black Italian leather pin-buckle strap is available for an additional $117.

To mark the revival of this storied line, 56 individually numbered watches — referencing the year of the company’s founding — are being offered with movements specially calibrated to COSC standards at no extra cost.

The only way to land one is to email the Ollech & Wajs reservations address (listed on the product page), with the special-edition watches distributed on a first-come, first-served basis.

Ollech & Wajs

Olech & Wajs P-104 Selectron

Specs

Case Size	39.5mm
Movement	Soprod Newton Precision caliber P092 automatic
Water Resistance	300m

• $2,023 at Olech & Wajs

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