The invention and establishment of the water clock in Egypt, at first glance, seems to be one of the best-documented developments in the history of ancient technology. A closer look at these clocks, however, reveals that their form and function have not yet been described sufficiently. Meanwhile, acquisition of three-dimensional data enables novel analysis of the preserved examples scattered all over the world. Regarding the fragmentary condition of most of the clocks, 3D scans are indispensable to investigate developments and functions of particular examples more closely and to ascertain the knowledge that existed about fluid dynamics around 1500 BC.