Twenty years after the original Planet Ocean, Omega finally did the one thing owners had been asking for the whole time: it put the watch on a diet. The fourth-generation Planet Ocean, launched in late 2025, measures 13.79mm thick — which doesn't just undercut the previous generation by more than 2mm, it makes this the thinnest Planet Ocean ever built, slimmer even than the 2005 original. Reference 217.30.42.21.01.001 is the new line's flagship: 42mm of sharply faceted steel, a matte black dial, black ceramic bezel, and still the full 600 metres.
New generation, new case — and, crucially for anyone shopping straps, a new size. Start there.
The new size: 21mm, and mind the generation
The fourth-generation Planet Ocean takes a 21mm strap — every one of the seven launch references does, across all three bezel colours and both factory configurations. That number is a break with the past: the 42mm Planet Oceans of 2005 through the 2010s all took 20mm. Same diameter, different generation, different strap. So the question that decides your order isn't "is it a 42?" — it's "which 42?" If the caseback is solid titanium and there's no date on the dial, you're holding the new one: select 21mm.
Two practical notes on our product pages: the width dropdown opens on 19mm, so change it to 21mm before adding to cart, and the buckle selector defaults to "No Buckle" — if your watch came on the bracelet, add a buckle at checkout (black is the natural match here). If your reference starts 217.32, your watch left the factory on Omega's rubber strap — the sizing and everything below apply identically. One honest engineering note: the new case sets its spring bars close to the body, which is exactly where a flexible rubber end works in your favour — rubber conforms where rigid ends can't, and with free returns and a lifetime warranty on rubber, trying the fit carries no risk.
The generation defined by what it removed
Omega didn't add its way to 13.79mm — it subtracted. The date window is gone, and with it the dial's only interruption. The helium escape valve, a Planet Ocean fixture since 2005, is gone. The display caseback is gone too, replaced by a solid grade-5 titanium back over an inner titanium ring, which took out thickness and weight in one move. Even the famous domed crystal has been flattened — a first for the line — sitting lower and staying more readable if the anti-reflective coating ever wears, a known sore point on older Planet Oceans.
What's left is the cleanest Planet Ocean dial ever shipped: matte black, with applied indices and arrowhead hands standing off it in real depth, and — the detail collectors noticed first — the open "stencil" 6 and 9 numerals, back for the first time since a beloved 2008 limited edition. There's even a stencil 4 in the bezel's 40 marker, something no Planet Ocean has worn before. The bezel itself upgrades to white ceramic indices for sharper contrast, and the whole case trades the old rounded shape for angular, faceted lugs that catch light off their brushed surfaces. On the wrist, owners consistently report it wearing closer to a 40mm watch. The movement is the no-date calibre 8912 — a METAS-certified Master Chronometer with twin barrels, chosen deliberately: this watch is aimed at people who rotate several watches and would rather never set a date again.
For orientation: the same watch exists with a blue bezel and with an orange bezel, one reference digit apart, and everything here applies to them too.
Why the strap question changed with this generation
Three reasons. First, thinness is now this watch's identity — and a rubber strap protects it. The factory bracelet's substantial end-links add visual and physical mass exactly where the new case worked hardest to lose it; a strap keeps the 13.79mm story honest under a shirt cuff. Second, the new bracelet leans into an integrated, seventies-inspired look that has split opinion — and with 21mm lugs and standard spring bars, converting the watch back to a classic two-piece profile is now a thirty-second job. Third, the deleted date and valve left a pure black-and-white canvas, which makes the strap the single easiest way to give the new Planet Ocean a personality Omega didn't ship.
The best straps for the fourth-generation Planet Ocean
1. Black with a white line — the stencil answer
The fourth generation's whole graphic identity is white-on-black: the stencil 6 and 9, the white ceramic bezel numerals, white lume on a matte black field. A black strap with a white centre line continues exactly that language down the wrist — one crisp line, nothing else — and its slim graphic keeps a deliberately thin watch reading thin. On earlier, busier Planet Oceans this was the quiet pick; on this dial it's the one that matches the design brief. The obvious first order.
2. Full black — keep it at 13.79
Omega spent a generation making this watch disappear under a cuff; a full black rubber strap finishes the job. Matte dial, black ceramic, black rubber — the watch becomes a single dark object that slides under a sleeve the way no Planet Ocean before it could. It's also the strap that makes the stencil numerals and steel case edges do all the talking. The everyday configuration.
3. Black with an orange line — twenty years of signature
Orange has been the Planet Ocean's calling card since 2005, and on the black fourth-generation model there isn't a trace of it — Omega saved the colour for a separate bezel version. A black strap with an orange line is the anniversary nod: the line's founding colour on the line's newest case, without touching the clean dial above it. If you own the watch because you've loved Planet Oceans for years, this is the one that says so.
4. Black with a red line — beyond the catalogue
Omega's own strap options for this generation stop at black and orange. A black strap with a red line is the bold move the catalogue doesn't make — and on this case it works precisely because the new design is so sharp-edged and monochrome. One aggressive line against all that angular brushed steel gives the watch a fast, technical edge no factory configuration offers. The pick for owners who want theirs to look like nobody else's.
The short version
21mm — not the 20mm every older 42mm Planet Ocean taught you. White line to match the stencils, full black to stay thin, orange for the heritage, red to go where the catalogue doesn't.
Every strap in our Planet Ocean collection ships with spring bars included and carries a lifetime warranty on rubber — with free worldwide shipping and no import costs, part of why more than 50,000 customers have trusted us with their watches. Guides to every other Omega we've covered live in the Omega strap guide hub. Omega spent twenty years making the Planet Ocean this wearable — now make it yours.
