Oris Aquis Date Calibre 400 Review: The Five-Day Diver

The Aquis is Oris's dive watch and the model the company is built on. The version reviewed here is the 41.5 mm Aquis Date in steel, with a blue dial, a rotating bezel carrying a ceramic minutes-scale top ring, and a steel bracelet with an extendable clasp. Oris describes the case as multi-piece — the construction that allows a separate top ring and the Aquis's distinctive stepped silhouette.

Functionally it is a three-hander with a date: hours, minutes, seconds, an instantaneous date with a quick corrector, and a stop-seconds function for setting it precisely against a time signal. No GMT, no chronograph, no power-reserve indicator. That restraint is the point — everything in the budget went into the movement and the case.

The headline number is the 120-hour power reserve. Five days means a watch taken off on Friday evening is still running the following Wednesday. If you own more than one watch, this is the single specification that decides which one you actually wear, and it is the reason the Calibre 400 matters: the Swiss divers it is priced against typically publish well under half that figure. Omega's caliber 8800 in the Seamaster Diver 300M is listed at 55.

The movement runs at 28,800 A/h (4 Hz), the industry-standard beat rate, so the long reserve is not bought by slowing the escapement down. Oris also lists a stop-seconds function, which sounds trivial and is not: it is what lets you set the watch to the second rather than to the nearest minute.

The case is 41.50 mm of multi-piece stainless steel. The crystal is sapphire, domed on both sides, with the anti-reflective coating applied on the inside only — a deliberate choice: an interior coating cannot be scratched off, at the cost of slightly more surface reflection than a both-sides treatment.

The bezel rotates and carries a ceramic top ring with the minutes scale. Ceramic is the right material here for the same reason it is on the Omega diver: a printed aluminum insert fades and scuffs, and a ceramic one does not. At this price, a ceramic insert is not a given.

The lug width — Oris calls it the interhorn width — is 22 mm, a common size, so the watch can be re-strapped without hunting. A rubber strap is the obvious upgrade for water use; our rubber strap guide covers what fits.

Oris rates the Aquis Date at 30 bar — 300 m. That is a real dive rating rather than a styling exercise, and it is the same figure Omega publishes for the Seamaster Diver 300M. Combined with the rotating bezel and its ceramic minutes scale, it is a watch you can dive with rather than one that merely looks like it.

Two things it does not have, and both are fine: there is no helium escape valve, which only matters for saturation diving from a pressurized habitat, and no depth gauge. If you want to understand what a given rating actually permits, our water resistance explainer is the five-minute version; the short answer is that 300 m covers everything a recreational diver will ever do.

The bracelet clasp is extendable, which is the detail that tells you Oris expects the watch to be used — an extension is what lets a bracelet go over a wetsuit sleeve, and it doubles as the easiest way to deal with a wrist that swells in heat.

Oris's warranty structure is the quietest reason to buy this watch. The standard term is two years. Oris states that it can be extended, free, to ten years by registering the watch with MyOris — and the company claims a ten-year service interval for the Calibre 400, against the three-to-five years most Swiss makers recommend.

Taken together, those two claims change the ownership math more than any dial detail. A mechanical service is a significant cost on a watch of this type — our luxury watch service guide sets out what the work costs — so a maker both doubling the recommended interval and covering the watch for a decade is making a meaningful commitment.

The honest caveat: Oris's page states the extension is free on registration, but does not spell out whether a watch bought outside the authorized network qualifies. If you are buying from a marketplace seller, ask that question before you treat the ten-year figure as part of the deal. Our guide to where to buy luxury watches online explains how that normally falls out.

Two gaps, and we would rather name them than write around them.

No case thickness.Oris's page for this reference gives a 41.50 mm diameter and a 22 mm lug width but no thickness. The Aquis is not a slim watch — the multi-piece case and 300 m rating guarantee that — and if you are between sizes, this is the figure you most need. Try it on, or measure your wrist first with our wrist measuring guide.

No gauss figure. Oris describes the Calibre 400 as having high anti-magnetism, which is a claim rather than a number. Omega certifies its calibers above 1.5 tesla — 15,000 gauss and publishes it; Oris does not quantify its own. If you work around MRI machines, speaker magnets or magnetic clasps, that difference is the whole decision, and the Omega is the watch with the receipt.

Oris lists this reference at $3,900at US retail. When we checked, Oris's own product page showed the reference as currently not available, offering a notify-me option instead — while a marketplace listing for the same reference was in stock at a substantially lower figure.

That gap is the Oris pattern, and it is worth understanding rather than simply enjoying. Independent Swiss brands without a resale floor discount in the channel, which makes them excellent watches to buy and poor ones to sell. The saving is real. So is the fact that a marketplace seller, not Oris, stands behind a watch bought outside the authorized network — and that is the same seller you would be asking about the ten-year warranty extension.

Live Amazon price: $2,499.00 — as of November 4, 2026. Prices move daily; the figure at checkout is the one that applies.

Listing sold out or changed? Search this reference on Amazon — the reference number is the only thing worth matching on.

Versus the Omega Seamaster Diver 300M.The Omega is the better-specified watch and the more expensive one: same 300 m, but METAS Master Chronometer certification, a published 15,000-gauss rating and a ceramic dial, against the Oris's five-day reserve and ten-year warranty. If certification matters more than reserve, buy the Omega — our Aqua Terra vs Seamaster Diver 300M comparison covers that family in detail.

Versus a Tudor. Tudor gives you COSC certification and the strongest resale in this price band. Oris gives you twice the power reserve and five times the warranty. Both are defensible; only one of them is a store of value, and our watches that hold their value guide is blunt about which.

Versus spending less. If the Aquis is above your budget, the honest step down is not a worse diver at the same price — it is a Swiss watch with a shorter reserve and a smaller name. Our best Hamilton watches guide covers 300 m Swiss-made automatics with 80-hour reserves at around a third of this money, and our best dive watches under $2,000 guide maps the rung between the two.

The Aquis Date Calibre 400 is the best movement-per-dollar proposition in the mainstream Swiss dive-watch market, and it is not close. A published 120-hour reserve, an in-house caliber from an independent maker, 300 m, a ceramic bezel insert, a sapphire crystal and a warranty Oris will extend to ten years is a specification sheet that costs considerably more elsewhere.

What you give up is third-party verification and resale. Oris publishes no chronometer certification and no gauss figure, and the brand has no secondary-market floor — the discounts that make it attractive to buy are the same discounts that will be waiting when you sell. Buy it to wear for ten years, which is exactly the watch Oris built. If what you want is a watch to hold, it is the wrong aisle: start with our best luxury dive watches guide, or with the references you can actually buy at retail today in our no-waitlist luxury watches guide.