There are four Seiko dive watches on a table. They are all the same model, with the license-plate-like name “SKX007.” Worn & Wound, a blog about affordable watches, called it “One of the most iconic divers on the market.” Seiko has never drastically changed the model’s design, never released special editions beyond a single blue-red bezel variant. Yet all four watches on the table are different — very different.
One of them has the look of a very traditional Japanese dive watch: black dial with funky white iridescent markings for the hours, a toothy bezel, a chubby crown growing at four o’clock for setting the time. The SKX007 next to that one has a dial that looks like metallic zebra hide. The SKX007 next to that is blacked out like a special-ops weapon. And the SKX007 next to that looks vintage military, busy with numerals that the first, more traditional Seiko diver lacks. If you look close you can see similar parts and a matching overall style. But they have different attitudes. If they were people they’d be distant cousins, not brothers, and a motley crew at that.
Again: Each watch on the table is a Seiko, but Seiko only made one the way it looks now.
It’s not a riddle. It’s the world of watch modding.
Traditional watchmakers are expected to design and build entirely new watches themselves. For watch modders — a small-scale cottage industry that’s gaining momentum thanks to web forums and increasing interest in affordable watches — completed watches are the starting point. A modder removes the separate pieces that make up the full watch — dial, bezel, hands, case back, crystal and more, sometimes even the movement — then replaces them with other parts to create new aesthetics atop the same base structure. Traditionally, modding was used to create replicas and homages to expensive, iconic watches like the Blancpain 50 Fathoms (which costs upwards of $10,000) using watches that cost a hundredth of the price.

The original Seiko SKX007, one of the most iconic divers on the market. It retails for around $200 and is a favorite among watch modders, who value its modularity, affordability and dependable movement.
But recently, some watch modders have gone further, blurring the line between watchmaking and watch altering. They’ve shifted from aping other watch designs to creating their own iconic and unique looks; swapping stock parts has given way to custom modifications like engraving and milling; some parts, like dials, are now custom made from scratch, in-house. Altogether it’s millimeters away from the new definition of “American watchmaker” written by companies like Weiss, Martenero and Shinola. They assemble their watches “in-house” around foreign-made movements and cases, bezels and dials they design themselves but whose fabrication they often contract out.
Most of the watches modders create are Seikos. Seiko thrives in the low-price mechanical market; modders are especially drawn to the SKX007 diver. It’s a meat-and-potatoes watch, beloved by customers and a joy to work with. It’s usually one of the first Seikos that modders tinker with, and a consistent seller.
“The SKX007 has the most parts, and the combinations kind of skyrocket on that model,” said watch modder Nick Harris, a 26-year-old phenom who’s grown his own watch-modding business out of his childhood home in Philadelphia. Harris has taken to avant-garde stylings and custom-engraved stainless-steel bezels. “If there was watch DNA, it would be far more modifiable with the SKX007 than other models.”
We asked three of the world’s best watch modders to go head-to-head, sending us their favorite mod of the SKX007. They made art by replacing bezels, dials and hands — used the dive watch as a canvas for creativity that ticks.