At Kintao, we honour watchmaking history by refining the innovations of the past. One innovation in particular led to the breakthrough in our first watch, the Chapter 1, with its internal rotating bezel controlled by the patented Unicrown system.
Today, a walk through the heritage of internal bezel watches: their ingenuity, their flaws, and how we improved the concept for today’s wearer.
Seiko’s SilverWave and World Time
In the early 1960s, Seiko introduced the SilverWave (1961), one of the world’s earliest watches with an internal rotating bezel controlled by a single crown. The design offered a slimmer case and protection from accidental bezel movement.
But the SilverWave’s bezel was friction-based, making precise adjustment difficult. Over time it loosened and lost accuracy. The Seiko World Time (1964) used the same elegant concept and met the same fate: friction bezels degrade, and reliability suffers.
Aquastar: Elegant but Imperfect
Around the same era, Aquastar pursued elegance with their own single-crown internal bezel designs, notably the Aquastar 63. Visually appealing and initially effective, they relied on the same friction bezels, and faced the same looseness, drift, and imprecision.
Modern Single-Crown Bezels: Still Facing Friction
Decades later, brands continue experimenting with single-crown internal bezels, from the Frédérique Constant Worldtimer to the IWC Aquatimer. Most still use friction mechanisms, so users still experience imprecise alignment, accidental shifts, and limited long-term reliability.
The Problem with Two-Crown Solutions
Recognising these limits, many watchmakers turned to two-crown designs. They offer slightly better control, but bring new compromises: extra bulk, more visual clutter, reduced comfort, and bezels that are still largely friction-based.
Dive Watches: Overbuilt for Everyday Life
Many watches with external rotating bezels are built for extreme underwater use that few people ever encounter. They tend to be heavy and bulky under a shirt cuff. For timing a meeting or a cooking interval, a heavy dive bezel feels like more than the task needs.
Chapter 1: The Unicrown Solution
Understanding these limits, we built something new. At 11mm thick, Chapter 1 integrates the Unicrown system, combining four functions — winding, 120-click internal bezel rotation, date setting, and time adjustment — through a single crown.
Unlike friction bezels, ours uses a clear, tactile 120-click system. Each turn is precise and reliable. The bezel stays exactly where you set it. Bezel adjustment (counter-clockwise) is cleanly separated from winding (clockwise), removing confusion, slippage, and accidental movement.
Thoughtfully Inspired, Thoughtfully Engineered
We haven’t forgotten the pioneering spirit of Seiko or Aquastar. We’ve embraced their vision, addressed their shortcomings, and added genuine mechanical innovation. The result is a new standard for what an internal bezel watch can be.
— The Kintao Team