Casio Duro 200 (MDV-106) MDV-106-1AV«Marlin»

The storyWhy this reference matters

The MDV-106 isn't a G-Shock or an Edifice: it lives in plain Casio Collection, home of the everyday resin digitals. And in there, since 2011, sits a 44 mm steel case with a screw-down crown, a screwed case back, a unidirectional 120-click bezel with an aluminium insert and 200 metres of water resistance. Written out like that it reads like the spec sheet from a different shop window, and that's exactly the point.

The fish on the dial and the case back is a marlin, and it isn't decoration: Casio uses it as a mark of diving fitness on models that reach 200 metres. The proof that it matters is that the MDV-107 exists — the same watch without the fish, because in certain markets Casio couldn't use the logo for licensing reasons. If you come across a Duro with no marlin, it isn't a fake: it's the international version.

The rest is what happens when a cheap product is well made. The dial has a sunray finish, the case mixes polished and brushed surfaces, the 2784 quartz has a quickset date and hacking, and the SR626 cell lasts around three years. More than six hundred thousand sold in its first decade. When Casio tried a small version in 2023 — the MDV-10, 38.5 mm and only 50 metres — the enthusiasts received it coldly: it had been stripped of exactly what made the 106 special.

SpecificationsThe numbers, in one table

IdentificationHow to tell it apart

The base reference is MDV-106-1AV, also written MDV106-1A: black dial, black bezel, resin strap. The MDV-106B variants come with coloured bezels (blue, green and red-blue two-tone combinations), the MDV-106G is the gold-toned one and the MDV-106DD comes on a steel bracelet. They all share the same case, module and water resistance, so the choice is purely cosmetic.

Real measurements, so you know whether it suits you: 44.2 mm wide, 48.5 lug to lug, 12.1 thick and a 22 mm lug width, which is an easy size to find. The crystal is flat mineral with no anti-reflective treatment, so it reflects a good deal. The bezel insert is aluminium with printed graduations and carries a luminous pip at twelve set in a small trapezium.

The 2784 module handles like a mechanical, which is a surprise in quartz at this price. First crown click: quickset date. Second click: the seconds hand stops and you can set it to the second. The case back screws down and carries the engraved marlin, the same fish printed on the dial.

CollectingWhat collectors check

Before you pay, turn the bezel all the way round. The 120 clicks should sound crisp, and a little back-play is normal on this watch: not a reason to haggle. What is a reason: skipped clicks, a dented aluminium insert, or a lume pip at twelve that has come unstuck. Check too that the printed graduations haven't been eaten by the sun.

Then the crown. Screw and unscrew it several times; if it catches or feels gritty, the thread is damaged and there go your 200 metres. The flat mineral crystal scratches easily and usually arrives marked; what matters is that there's no chip at the edge, because that does compromise the seal. And if the watch has sat for years with a dead battery, open it or have it opened before you trust it.

On value, be realistic: this doesn't appreciate. Where the MDV-106 has created a market is in mods — bezel inserts, sapphire crystals, hands and straps. There it's worth deciding what you're actually buying, a factory-original example or one that's been worked on. A modified Duro isn't worth more than an untouched one unless the work is faultless and that particular result is exactly what you want.

Common questionsWhat people ask us about this reference

Keep readingWhere to go from here

Close relativesThe ones it gets confused with