IWC Portugieser Chronograph IW371604

The storyWhy this reference matters

The Portugieser was not born from a designer's whim but from an awkward commission. In 1939 two Portuguese importers, Rodrigues and Teixeira, asked IWC for a wristwatch with the accuracy of a marine chronometer. The only way to manage it was to put a pocket-watch calibre inside — the 74, with its big balance and generous inertia. Out came reference 325: 41.5 mm of Staybrite steel at a time when a gentleman's watch measured about 33. Six hundred and ninety were built over forty-two years.

The family then slept until 1993, when IWC marked its 125th anniversary with reference 5441 — 1,750 pieces, hand-wound. The chronograph arrived in 1998 as reference 3714, running a calibre 79350 that was really a modified Valjoux 7750, with just two registers, at 12 and at 6. It stayed all but untouched for twenty-two years, an eternity in modern watchmaking, and ended up the best-selling model in the whole collection.

Reference 3716 appeared in 2020, and with it the calibre 69355 — the first in-house chronograph IWC put into normal production rather than into an anniversary run. Column wheel, vertical clutch, directly driven seconds, 46 hours of reserve. Outside, little changed: the same 41 mm, the same sunken registers, the same quarter-second scale on the rehaut. Inside, IWC stopped buying the heart of its own best-seller.

SpecificationsThe numbers, in one table

IdentificationHow to tell it apart

The IW371604 is the classic one: silvered dial, applied Arabic numerals and rose-gold-toned leaf hands, with the chronograph and minute hands blued so they read against the pale background. Its immediate sibling, the IW371605, carries the same silvered dial but with blue hands instead of gilt. In a bad angled photograph the two are easy to muddle; the hands are the only reliable tell.

To be sure you are looking at the 2020 generation and not an earlier one, turn it over. The 3716 has a sapphire case back, and through it you can see the 69355 with its column wheel and Côtes de Genève. The case is 41 mm across by 13 mm tall, rated to 3 bar: this is a dress chronograph, not a pool watch, whatever the diameter suggests.

Watch out for the 2024 references, which share the calibre and the case but not the dial: IW371624 (Dune, steel), IW371625 (Obsidian, 5N gold) and IW371626 (Horizon Blue, white gold). Same machine in a different suit, and second-hand listings mix them up with the 604 constantly.

CollectingWhat collectors check

The first thing an experienced buyer looks at is the back. If you cannot see the movement it is not a 3716, and that changes the whole conversation: the earlier 3714, on a Valjoux base, is a different watch — cheaper to service, with twenty-two years of production behind it, which means plenty of supply and an enormous spread of condition.

On the 604 specifically, the silvered dial is both the strong point and the weak one. Pale finishes give away any moisture stain and any smear of adhesive from a marker that has shifted; look at them under a loupe and against the light. Check too that the quarter-second scale on the rehaut is crisply printed and properly aligned with the markers — a rotated rehaut usually means the watch has been opened carelessly.

The 46-hour reserve is the figure that never made the leap the rest of the industry did. IWC now sells calibres running 120 and 168 hours, and this one stays where it was. Not a fault, but know it before you leave the watch in a drawer over a long weekend. The top of the case is polished and scratches if you look at it, so an example with its edges still sharp is worth more than a "like new" one that has in fact been through the polisher.

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Close relativesThe ones it gets confused with