Galapagos marine iguanas are masters of energy efficiency. They bask in the sun on the baking hot volcanic rock for hours on end, storing the energy they need for their strength-sapping dives. In cold water they reduce their energy requirements by slowing down their heartbeat. The conservation of energy, incidentally, plays an important role not only biologically but also in watch technology. In order to advance its large month display discs, the Aquatimer Perpetual Calendar Digital Date-Month requires more power than the in-house automatic 89801 calibre can provide. For this reason, every night when the date display is advanced, the quick-action switch taps a little energy and stores it until the end of the month. With its impressive case diameter of 49 millimetres, the Aquatimer Perpetual Calendar Digital Date-Month is the second-largest wristwatch in the history of IWC – just behind the Big Pilot’s Watch launched in 1940. The unusual combination of materials – 18-carat red gold with rubber-coated titanium – gives the watch an appearance which is at the same time luxurious and sporty. The date and month discs have semi-transparent perforated covers that provide a view of the complex mechanism within. The designers took their inspiration for this particular element from the filter systems that are omnipresent on all submarine vehicles. The rotor behind the see-through sapphire-glass back is distinctly functional-looking and likewise alludes to the reliability of research submarines. The exclusive flagship of the new collection is limited to 50 watches and water-resistant to 10 bar.