Hajime Asaoka has announced a new diving watch that features two cases.
Similar to the Omega Speedmaster Alaska Project, which uses an inner case, and removable outer case, for extreme thermal protection, the 2026 Kurono Diver’s watch uses a traditional inner watch case, and a removable outer case.
Except, with the Kurono Diver’s the purpose of the outer case is to prevent water from entering the case. The inner case is rated to 50 meters of water-resistance, and once the outer case is installed, the water resistance rating increases to 100 meters.
Asaoka states, “Upon first encountering this timepiece, the most immediate observation is likely the absence of a crown.
The crown has always been the Achilles’ heel of diving watches. To address this, various innovations have been employed — from screw-down mechanisms to locking levers. Yet, the ultimate solution is to eliminate the crown entirely.
Thanks to the high winding efficiency of modern automatic movements, a watch worn regularly rarely stops and maintains excellent precision. Once the time is set, the need for crown manipulation is virtually non-existent. It was this realization that inspired my concept: to encapsulate the entire wristwatch within a dedicated waterproof casing.”
“When diving — or in any situation requiring absolute water resistance — placing the watch into this outer diving case transforms it into a professional tool capable of withstanding depths of up to 300 meters. This is the defining characteristic of the Kurono Diver’s.”
Driven by a 4Hz automatic Miyota caliber 90S5, with 24 jewels, and a 40-hour power reserve, the movement will be reliable, yet nothing chronometer level, as you might expect for such a so-called professional tool.
The inner case, which is cushion-shaped, measures 35 x 35 mm, and 9 mm thick, with a lug-to-lug of 37.4 mm. This is the first cushion-shaped case from Kurono Tokyo. Once you install the outer case, the watch dimensions increase to 46 mm in diameter, 13.5 mm thick, and 56.7 mm lug-to-lug. This is the largest case Kurono Tokyo makes.
Asaoka says, “The development of this timepiece spanned many years, involving exhaustive field tests and high-pressure trials. To verify our peak performance metrics, we conducted rigorous evaluations in collaboration with official Japanese public research institutes to ensure this exceptional level of water resistance.”
Interestingly, the hand set consists of blued steel with a cathedral design, which is something you don’t see often in a dive watch.
“Operation is intuitive and seamless. The bezel functions as a threaded lid; using a dedicated opener, it can be easily unscrewed counter-clockwise. Furthermore, the bezel features a unidirectional rotation mechanism — an essential for divers — to track elapsed time while preventing the case from accidentally loosening. For lighter use, the case can be opened or closed by hand without the tool; so long as the bezel remains secure when tested counter-clockwise, the seal provides water resistance equivalent to 10 ATM.
The bezel is crafted from Extra Super Duralumin, finished in a deep red through hard anodizing. This specific shade of red is designed to maximize contrast with the white-engraved indices, ensuring peak legibility underwater.”
The inner watch features a leather strap (19 mm/16 mm) with quick-release design, allowing for attachment and removal without tools, which is required in order to place the watch head in the outer (diving) case, that has a rubber strap (24 mm/ 22 mm) attached.
The Kurono Diver’s cases are stainless steel, and the watch is made in Japan. Retail price is $3,105 in the US, with tariffs included ($2,700 without tariffs). This is marketed as an application piece (whether the demand truly justifies this, in the post-pandemic era, is questionable), and applicants with recreational (or higher) diving certifications (e.g., PADI, SSI, NAUI, etc.) will be prioritized, but not guaranteed to receive an allocation.
Learn more at Kurono.
Final Thoughts
For those who like the dual-case design of the Omega Speedmaster Alaska Project timepiece but that want something more wearable, or for anyone interested diving watches, or perhaps the eccentric watch collector in search of a complicated case design, the Kurono Diver’s offers an option to own something unique, in a sea of ubiquitous diver’s watches.
Photos by Kurono Tokyo.
