Quick answer

IWC does not make a watch called the Aquatimer Deep Time. The name is a mix-up. IWC built three Aquatimer dive watches with a mechanical depth gauge: the Deep One (1999), the Deep Two (2009, ref. IW3547) and the Deep Three (2016, ref. IW3557). Most replica listings that use the words "Deep Time" sell a case and dial that copy the Deep Two or Deep Three housing. The depth gauge on those copies does not work. On the real watch, the gauge is a spring-loaded piston that moves a hand and records the deepest point of a dive.

What the real watch does

Deep Two: stainless steel, 46 mm, depth gauge to 50 m, a second hand that holds the maximum depth reached, and a reset pusher. Deep Three: titanium, 46 mm, same 50 m gauge range, crown guard, wider bracelet. Both run automatic movements with a module for the gauge. IWC stopped production of the Deep line, so every piece on the market is pre-owned.

What fakes copy

  • Case size and profile. Copies list 46 mm and land within 1 mm.
  • Dial layout: inner bezel, depth scale printed in white and red, max-depth hand at the 6 or 9 position depending on the model.
  • Caseback engraving: reference number, serial, "Aquatimer" text.
  • Box and papers. Some sellers print cards that match the case number.

What fakes miss

  • The gauge. A piston that reads water pressure needs tight tolerances. Copies use a fixed hand or a hand tied to a dummy lever. Water gets in.
  • Case height. The Deep Two is about 15 mm thick. Most copies are thinner because the module is missing.
  • Weight. Steel copies run light. A titanium Deep Three should also feel light, so weight is not a test on that model.
  • Hands and lume. Copy lume glows for minutes, not hours.
  • Crown action. Real crown threads turn smooth for several rotations. Copies feel gritty after one turn.

Prices

Used Deep Two and Deep Three pieces trade from four figures into low five figures in USD, based on condition, box and papers. Replica prices sit between $80 and $400. A seller who asks four figures for a copy is not selling at copy prices.

How to check one

  1. Ask for a photo of the gauge hand under water pressure. Few sellers can produce one.
  2. Compare the caseback number to IWC service records. IWC can confirm a reference and serial.
  3. Weigh the watch. Look up the listed weight for the reference.
  4. Check the date font and window position against photos from the maker.
  5. Have a watchmaker open the case. The module is the fastest tell.

Unknown: no public count exists for how many Deep Two or Deep Three copies were made, and no factory claims a working depth gauge on a copy.