Two estimates of the precision of our globular cluster velocities. The left panel compares our data to those of the high-precision measurements of Strader et al. (2011). The solid red points denote objects that differ from zero by more than three times the internal precision of the measurements; three additional systems have velocity discrepancies that fall well off the plot. The right panel shows the velocity differences for clusters observed in more than one Hydra setup. The scatter in these data is 7.6 km s ⁻¹. The solid points display old (globular) clusters; open circles show younger systems.