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And in more dimensions than one.

The Apple Watch Ultra is built more like a tank than the sleek Apple Watches that came before it. It's the brand's most rugged smartwatch so far, and its specs and aesthetics seem genuinely function-first. Traditional dive watches and other action-ready timepieces have long included the same kinds of features as the Ultra: a large crown with grippy grooves, "crown guards" for extra protection — and beefy dimensions.

It's the biggest Apple Watch yet, but what does its 49mm measurement actually mean for how well it'll fit on your wrist? Larger watches allow for more readable displays in less-than-ideal situations, as well as the ability to build in more durability — but wearability can be the tradeoff. Shown during Apple's announcement, the Ultra certainly looks bulky, even on the wrists of divers and athletes, almost like an actual dive computer.

If you want a quick reference, 49mm is longer than two US quarters placed end to end (48.52mm), but there's always more to a watch's wearing experience than cold, hard numbers will tell you. Here's what you need to know.

The famous Rolex Submariner is an example many will be familiar with: its current production version measures 47.6mm, end-to-end ("lug-to-lug"). That 1.4mm discrepancy might not sound like a lot (and the Sub wears prominently but well), but in the context of a wrist, millimeters can make a difference.

Another handy reference might be the famous square G-Shock á là the GWM5610. That's 46.7mm where as the "CasiOak" (GAB2100) is closer at 48.5mm (of course, some G-Shocks are much larger). The MoonSwatch and the Omega Speedmaster Moonwatch have identical proportions and measure 47.3mm. They're all smaller than the Apple Watch Ultra, and side by side you'll likely find that they look smaller, too, despite that we're only talking about millimeters.

Yes, you can expect that the Apple Watch Ultra will have a considerable wrist presence. Here's the kicker: if Apple's measurement of 49mm only includes the case body itself and not the strap attachments, you can expect the Ultra to wear even larger (when using straps with attachments rather than those that clip directly to the case).

It's a matter of taste, but also of dimensions and practicality. If the watch's silhouette extends beyond that of your wrist, it's probably too big. Traditionally, watch companies only give you width measurements, while Apple offers the case's length. Frankly, Apple's approach is far more useful and is the measurement that will best indicate how well a watch will fit on your wrist.

Along with the Apple Watch Ultra's measurement of 49mm, its other dimensions are also chunky. It's got a width of 44mm and a thickness of 14.4mm — and the latter is important. Watchmakers can often get away with large sounding watches when they keep them nice and thin, but when you start adding vertical height is when a watch can get unwieldy.

For comparison: The Rolex Submariner is only 12mm thick. Chronographs are known to be bulkier due to more complicated mechanisms inside, but the Omega Speedmaster Moonwatch (and the MoonSwatch) is only 13.25. Surely, Apple is packing a lot into the Ultra's case (like a big ol' battery), but it's also thicker than the G-Shock GWM5610 (12.7mm) and the "CasiOak" GAB2100 (11.9mm).

It's worth noting that titanium is lightweight and certainly helps a large watch wear easier. Of course, we'll bring you our impressions of the Apple Watch Ultra and how it actually wears in real life.

We trust that Apple considered ergonomics carefully in developing the Ultra, but unless you're very familiar with your own wrist size, watch sizes in general and how they fit, try before you buy.