IWC Aquatimer Perpetual Calendar Digital Date Month

IWC Aquatimer Perpetual Calendar Digital Date Month

by Michael Weare
IWC, Over $30,000, SIHH

Open-worked this, skeletonised that, lots of peering into the labyrinthine inner workings of tourbillons; SIHH 2014 seemed to be replete with the art of such things this year. With manufactures going so far as to comprehensively redesign movements so as to be smaller and thinner and more delicate with gossamer-like strands of ingeniously worked precious metals lending movements the appearance of being suspended in air.

It’s all extremely difficult to create, and shows the breathtaking expertise of some of Switzerland’s finest, but sometimes you just want a big, powerful no nonsense diver that you strap on your wrist and look like a real man. The IWC Aquatimer Perpetual Digital Date Month is engineered for men, and no woman should be seen wearing it.

IWC Aquatimer Perpetual Calendar Digital Date Month

IWC Aquatimer Perpetual Calendar Digital Date Month

The watch is clad in a reassuringly resilient rubber-coated titanium with an 18-carat red gold bezel. It’s an unusual look, but it works. At 49mm, it’s the unashamed chunky flagship watch of the new Aquatimer collection. Incorporating some nifty technology, it is in fact the second largest watch IWC has ever created. The largest was a Big Pilot’s watch created in 1940.

The watch features small hacking seconds for synchronising your watch with other dive team members and a leap year display at 6 o’clock.  The hours and minutes of the flyback chronograph combine in a totaliser at 12 o’clock.  Now there is a bit of open-worked magic to this timepiece as well. When you gaze at the large double digit day and month displays you can enjoy the sight of the discs slowly rotating under the honeycomb mesh.  The designers took the idea for this by closely inspecting the mesh on submarine filter systems. As for the digital date system for hours and minutes, it harks back to the Pallweber system originally developed by IWC as long ago as 1885.

IWC Aquatimer Perpetual Calendar Digital Date Month - Caseback

IWC Aquatimer Perpetual Calendar Digital Date Month – Caseback

The new SafeDive system incorporated into the watch features both internal and external unidirectional rotating bezels, and there’s some very clever technology created to cope with the energy sapping demands of the IWC-manufactured 89801 calibre, as it has a lot of work to do. Those large rotating discs need more juice than the movement can really supply, so every night the quick-action switch taps a little energy and stores it for the end of the month to manage that change of day and month when the date display is advanced. Come the end of the month, the tension in the spring is fully loaded, and it’s then that all the energy is released. With regular wear the movement can store up to 68 hours power reserve. IWC designers claim to have found inspiration for this particular idea from the way in which iguanas store heat while lying on baking hot volcanic rocks by day. They (the iguanas and presumably not the IWC designers) need to sit on the rocks doing nothing for hours at a time in order to store energy to go diving for food.

IWC Calibre 89801

IWC Calibre 89801

Water resistant to 100 metres, the watch hands and dial feature luminous material for reading underwater. The hardest thing to come to terms with about this stunning watch is the production quantity. Just 50 have been made at a price of $49,700, however, it forms part of a family of seven new IWC Aquatimers, some of which will surely be produced in sufficient quantities to acquire one.

IWC Aquatimer Perpetual Calendar Digital Date Month – Specifications

Reference: IW379401 (Limited edition of 50 watches)
Case Material: 18-carat red gold and rubber-coated titanium
Bracelet/Strap: Black rubber strap with alligator leather inlay
Dial Color: Black


  • IWC-manufactured 89801 calibre (89000-calibre family)
  • Mechanical chronograph movement
  • Self-winding
  • 68-hour power reserve when fully wound
  • Mechanical external/internal rotating bezel with SafeDive system
  • Perpetual calendar
  • Stopwatch function with hours, minutes and seconds
  • Flyback function
  • Small hacking seconds
    Author Bio

    Articles by Michael Weare


    Michael Weare hails from an international advertising agency background where he handled several well known and highly desirable watch brands; handled, but sadly never got to keep. However it's this exposure that gave him a lasting fascination for watches. Michael was Editor of Click Tempus for over 2.5 years and is now in the same role at Watchuseek, the web's largest watch forum.