IWC Deep One ref. IW3527 - Serial 2771399 (Pre-Owned)

Presenting a watch from the genius of Richard Habring before he was making watches with his own name on the dial. The IWC Deep One features a Depth Gauge complication invented by Richard during his tenure as project leader at IWC. 

Furnished with titanium bracelet which can easily accommodate a 7.5" wrist, and original OEM grey velcro strap... Editior's note: I absolutely love wearing it on the velcro strap. I wore the watch for 2 weeks straight before photography and listing it here.

Titanium case measures 42.8mm x 14.75mm x 49mm lug-to-lug.

IWC reference IW3527, aka IW352701, Serial 2771399 is currently in stock. No box, papers, or pump tool. 

Watch was tested June 2024 as running accurately and water resistant to 100M. This watch is to be sold "as-is" without warranty by Horology By The Sea and is in reflected in the price many thousands of dollars less than anywhere else. 

Illustration in last slide credit to Monochrome Watches as well as description of the watch below:

"Now, about the three sharpy-knurled crowns of the IWC Deep One IW3527, also in titanium. The top-most crown is used to set the dive bezel. This crown is unidirectional and has one-minute clicks. IWC developed an additional fail-safe system to prevent actual shortening of the dive time: when the watch is submerged beyond several meters, the external pressure acts on the crown and deactivates it. This crown has another trick up its sleeve. Pressing it resets the maximum depth gauge. The middle crown is engraved with IWC’s historical fish symbol (the sought-after fish crown) and is used to set the time and date. Finally, we come to the lower crown. Pushing the crown resets the calibration of the depth hands to zero, which becomes necessary for high-altitude diving (think mountain lakes). Close inspection of the crown reveals nine small holes drilled into it. This is the Deep One’s true party trick and is the secret behind the depth gauge. 

Underpinning the depth gauge is a mechanism named after the French scientist Eugène Bourdon in 1849. A Bourdon tube is a thin-walled metal tube that allows the entry of pressure into it: as pressure enters the device, the metal tube straightens. This movement is transmitted via a lever to the dial side of the device displaying the pressure. 

To translate the same principle to a depth gauge: instead of letting pressure enter the gauge, it allows water to enter a sealed tube – as the tube fills with water, it straightens; in shallower water, it coils tighter. The movement of the tube is transmitted via a toothed rack system (like you would find in a retrograde complication) to the dial of the gauge. The maximum depth reading of 45 meters of the Deep One is linked to the Bourdon tube’s characteristics – the system is most accurate at depths of 40 meters or less."