Short answer

A replica IW3716 is a copy of the IWC Portuguese Chronograph, a 41mm steel bicompax watch with a chronograph minutes counter at 12 and running seconds at 6. Good copies run on a reworked Asian 7750 chronograph movement and sell for roughly $250 to $900. Cheap ones run $100 to $200 and get the proportions, hands and dial print wrong in ways you can spot in ten seconds once you know where to look.

What the real 3716 is, so you know what is being copied

The 3716 family is the classic Portuguese Chronograph. Stainless steel, around 40.9mm across and about 12.3mm thick, which is thin for a chronograph and the main reason the case looks elegant rather than chunky. Inside sits caliber 79350, an ETA/Valjoux 7750 base that IWC reworked, beating at 28,800 vibrations per hour with around 44 hours of reserve.

• Bicompax layout: 30 minute chronograph counter at 12, small seconds at 6
• No date window breaking up the dial
• Domed sapphire crystal, anti reflective coating on both faces
• Sapphire display back showing the decorated 79350
• 30m water resistance, which means splashes only
• Applied numerals, feuille hands, railroad minute track

Dial colors move between silver white with blued or gold hands, black, blue and a few limited runs. The case stays the same. That matters, because a replica that nails the case shape works for almost every version.

The three replica tiers

Budget, about $100 to $200

Quartz or a rough 7750, mineral glass, painted hands, hollow end links and dial text that sits too low or too thick. The subdials often do not function as they should. On some, the 12 o'clock counter is a 12 hour totalizer instead of a 30 minute one, which is an instant tell if you run the chrono.

Mid range, about $250 to $450

Sapphire crystal, decent Asian 7750 with the correct 12 and 6 layout, real leather strap. Case finishing is close but the lugs tend to be a little soft and the caseback is often 1mm or 2mm too thick. This is where most people stop and honestly it is the value point.

Top tier, about $500 to $900

A reworked 7750 built to mimic the 79350 layout, correct 40.9mm case, double sided AR coating, heat blued hands on the blue dial versions, engraved caseback with a plausible reference number, and a croc style strap with a matching pin buckle. At arm's length these read as the real thing. Under a loupe, the printing and the movement decoration still give it away.

How to check one before you pay

• Ask for the case diameter and thickness. Anything over 14mm thick is a 7750 in a fat case, not a 3716 profile.
• Watch the small seconds at 6 in a video. It should sweep smoothly, roughly eight steps per second. A one second tick means quartz.
• Run the chronograph. Start, stop and reset at the pushers. It should snap, not mush, and the 12 o'clock hand should complete a full circle in 30 minutes.
• Look at the hands at an angle. Proper feuille hands are thin and leaf shaped. Blued steel shows a deep even blue, not a purple paint shimmer.
• Check the dial print. The logo and the text under it should be crisp with even spacing, not fat and blurry.
• Look at the crystal edge. Double AR coating gives a faint blue tint and near invisible reflections. Single coating washes out and reflects more.
• Ask about the strap and buckle. A $700 replica on a plastic feeling strap is a mismatch, and it usually means the seller cut corners elsewhere.
• Confirm the movement by photo. An undecorated rotor and a bare grey plate mean nobody tried.

The movement is where the money goes

The Asian 7750 naturally puts running seconds at 9 o'clock and elapsed hours at 6. The Portuguese needs running seconds at 6 and a 30 minute counter at 12. Any replica with a working, correct dial layout has had that movement modified or rebuilt around a different plate. That work is most of the cost difference between a $200 watch and a $700 watch, and it is also the part most likely to need a service down the road. Chronograph modules are fussy. Stop the chrono when you are not using it and it will last longer.

Red flags

• Stock photos only, no real pictures of the actual watch
• Claims of Swiss made movements at budget prices
• No mention of thickness, caseback or movement type
• Sellers who will not show a running chronograph on video

Living with one

Treat it like a mechanical watch, because it is one. Keep it away from water, wind it gently, and expect a service eventually. Parts for a modified 7750 are not hard to find, but not every watchmaker wants the job. Buy the seller more than the watch, and go in knowing a replica is a $600 watch that looks like a $7,000 one, not a $7,000 watch. If you want the real thing, save for the real thing.