Since its initial debut in fall 2020, Oris’ in-house Calibre 400 automatic movement has been gradually working its way through the brand’s lineup as its new de facto flagship three-hand powerplant. As one of the cornerstones of Oris’ lineup the Aquis diver was a natural choice to debut the new movement in late October 2020, but at that time the Calibre 400 was restricted only to full size 43.5mm models. As summer 2021 ramps up and enthusiasts search for a new vacation-ready sports watch, Oris takes the next logical step and brings the Calibre 400 to the smaller 41.5mm Aquis line. Rather than reinventing the wheel, the new Oris Aquis Date Calibre 400 41.5mm series lets the performance of its new movement speak for itself while maintaining the classic Aquis look.
As the name suggests, the stainless steel case of the Oris Aquis Date Calibre 400 41.5mm line measures in at 41.5mm. The modern and slightly unorthodox Aquis shape with its slab case sides, heavy wide crown guards, and short angular semi-integrated lugs is shared with previous 41.5mm Aquis models, and like those iterations, the unique proportions of the Aquis may make the case measurements somewhat misleading. In practice, the shrink-wrapped profile of the mid-case without any outward flaring coupled with the abrupt downward slant and short reach of the lugs tend to make the Aquis series feel substantially more compact on the wrist than more traditional diver styles. As with previous versions, the heavily toothed unidirectional dive bezel is noticeably wider than the case beneath it, leading to a slight overhang which should aid grip. The ceramic bezel insert features a bright, legible white diving scale on a base of black, navy blue, or deep forest green. Around back, Oris includes a sapphire display window to showcase the new in-house movement, but despite this more vulnerable element the case is rated at a hefty 300 meters of water resistance.
Like the cases, the dials of the new Oris Aquis Date Calibre 400 41.5mm series keep the overall look familiar while subtly hinting at the new movement within. The most notable difference between these dials and the dials of previous Sellita-powered 41.5mm variants is the 6 o’clock date window. Where the smaller diameter of the Sellita movement forced the date display of those models inboard slightly, leading to both a date window and a shortened index at 6 o’clock, the larger date wheel of the Calibre 400 pushes the 6 o’clock window directly in line with the rest of the faceted applied hour indices, eliminating the 6 o’clock index entirely for a cleaner and simpler look. Outside of this small change and a “5 Days” line of text at 6 o’clock, the dial layout is unchanged, with the familiar rounded sporty alpha handset and indices making a return. Also like many previous Aquis models, all three versions of the new Aquis Date Calibre 400 41.5m series use a sunburst dial finish. Buyers can choose between a dark anthracite gray tone, an oceanic sunburst blue, or an emerald green, which feels deep and intense in initial images.
The in-house Calibre 400 automatic movement inside the Oris Aquis Date Calibre 400 41.5mm series is a major step forward for the brand’s movement-making capabilities, especially for its core offerings. Although accurate within COSC chronometer standards at -3/+5 seconds per day, Oris interestingly does not submit these movements for certification. Beyond the excellent accuracy, the Calibre 400 offers magnetic resistance of up to 2,250 gauss, more than 11 times the current ISO standard for anti-magnetism. This durability is continued through the automatic rotor, which replaces the complex and often delicate ball bearing system with a mechanically simpler and more robust tongue-and-groove metal slide bearing system which Oris claims produces far less wear. Power reserve performance is robust as well, with twin mainspring barrels producing a hefty 120 hours of power reserve at a 28,800 bph beat rate. Oris also touts the longevity of the Calibre 400 platform, recommending a service interval of 10 years rather than the more standard five recommended years between services. While the Calibre 400’s performance is undeniably robust, the movement’s finishing is simple, bordering on industrial. A matte-blasted three-quarter bridge covers up most of the real estate beneath the display caseback besides the balance wheel, and the signed skeleton rotor bears a clean brushed finish.
The semi-integrated stainless steel three-link bracelet with dive extension has historically been a hallmark of the Oris Aquis’ design, and the new Aquis Date Calibre 400 41.5mm line continues the trend. With a sharply tapering profile that flows from a narrow clasp directly into the case and bright polishing on the outer links to visually match the lugs, this bracelet offers a unique and eye-catching look. Oris keeps the bracelet from appearing too monotone or flashy thanks to vertically brushed center links. For those that prefer straps, all three models in the new line can also be optioned with the brand’s signed textured black rubber strap, which also includes a folding clasp and dive extension for a modern and functional sporting look.
While some may decry the lack of visual distinction from the brand’s more affordable Sellita-powered options, the new Oris Aquis Date Calibre 400 41.5mm series delivers impressively robust capability to a more compact diver design without compromising the signature Aquis look. The Oris Aquis Date Calibre 400 41.5mm line is available now through authorized dealers at an MSRP of $3,300 on rubber and $3,500 with the stainless steel bracelet. For more details, please visit the brand’s website.