Short Answer

IW371786 sits inside the IWC Pilot's Watch Chronograph 3717 family. A genuine 3717 runs a 42 mm steel case, a Valjoux 7750 based calibre 79320, a day and date window at 3 o'clock, and a running seconds subdial at 9. Most watches sold online under the name "IW371786" are not genuine. Tells: a quartz movement, a 40 mm case, a printed logo, a white date wheel. Genuine steel examples trade used at USD 3,000 to 4,500. High-tier replicas sell at USD 350 to 700 and can pass a glance at arm's length. They do not pass an IWC service center inspection.

What the 3717 Reference Is

IWC built the Pilot's Watch Chronograph 3717 from 2006 until the 3777 replaced it. Core specs:

  • Case: 42 mm stainless steel, 14.7 mm thick, 60 m water resistance
  • Crystal: sapphire with anti-reflective coating on both faces
  • Movement: IWC calibre 79320, 25 jewels, 28,800 vph, 44 hour power reserve
  • Dial: black, luminous Arabic numerals, 12-hour counter at 6, 30-minute counter at 12, small seconds at 9
  • Caseback: solid steel, engraved with reference number and serial number

IWC's public catalog shows sub-references such as IW371701, IW371704, IW371705 and IW371708. IW371786 is not among the numbers in most published lists. A seller who uses it should supply a caseback photo and a service record.

How to Spot a Fake or Replica

Movement

Ask for a photo of the caseback with the back removed, or a video of the chronograph start, stop and reset. A gen 79320 snaps back to zero in one motion. A quartz fake ticks once per second. A low-grade automatic sweeps but the chronograph seconds stutter. The 79320 is a modular 7750, so the pushers have a firm click and the rotor swings with a slight wobble when the watch is shaken.

Case and Crystal

The gen measures 42 mm across without the crown. Many fakes measure 40 mm. The gen crystal carries AR coating on both sides, so the dial takes on a blue tint at an angle. Most fakes have coating on one side or none, and the dial reads flat grey.

Dial and Hands

The IWC logo on the gen is an applied polished metal piece. On most fakes it is printed and sits flush with the dial. The date and day wheels on the gen are black with white text. Many fakes use white wheels or a day font that does not match the date font. The hand set differs between the 3717 and the later 3777. Some fakes use 3777 hands on a 3717 dial. Lume on the gen is Super-LumiNova and glows blue-green within seconds of a flashlight charge. Fake lume glows weak or not at all.

Caseback and Numbers

Engraving on the gen is deep and sharp, and it matches the reference in the IWC service record. Engraving on fakes is shallow or laser etched. Check that the serial on the caseback matches the serial on any IWC paperwork. An IWC service center can confirm a serial and will flag non-genuine parts during a service estimate.

Replica Market Tiers

  • Low tier, USD 50 to 120: quartz movement, 40 mm case, mineral glass, printed logo, wrong subdial spacing.
  • Mid tier, USD 150 to 350: Asian 7750 or DG4813, 42 mm case, sapphire crystal, dial printing too thick.
  • High tier, USD 400 to 700: clone 7750, correct case profile, double AR coating, engraved caseback with a plausible serial. A few use a real ETA 7750 with no IWC markings.

No factory makes a true clone of the IWC 79320. High-tier replicas run a 7750 with decorative finishing. That is the main reason a replica fails an IWC service inspection: the movement is not an IWC movement and the parts do not interchange.

Buying Checks

  1. Photograph the caseback, the dial straight on, and the movement if the seller permits.
  2. Measure the case with calipers. 42 mm, not 40 mm.
  3. Run the chronograph. Reset should be instant and land on 12.
  4. Check the serial against IWC records or a service center.
  5. Check the price. A genuine 3717 in steel on leather sells used at USD 3,000 to 4,500. A listing at USD 600 is not genuine.

What Is Not Known

IWC does not publish a full historic reference list online. The exact dial and strap configuration for IW371786 is not documented in the sources reviewed here. Treat that number as unverified until IWC confirms it.