In this special guest feature, Bob Fletcher from Verne Global reflects on how liquid cooling technologies on display at SC19 represent more than just a wave. Bob Fletcher is VP of Artificial Intelligence at Verne Global. Perhaps it is because I returned from my last business trip of 2019 to a flooded house, but more likely it's all the wicked cool water-cooled equipment that I encountered at SC19 that I'm in a watery mood! Many of the hardware vendors at SC19 were pushing their exascale-ready devices and about 15% of the devices on a typical computer manufacturer's booth were water-cooled. Adding rack-level water cooling is theoretically straight forward, so I spent a few minutes checking out the various options. The first thing I noticed is that the chilled water from outside terminates in a Cooling Distribution Unit (CDU) which then has its own water-cooling loop which is connected to the computing equipment.