Antarctic krill (Euphausia superba) are a key link in the Southern Ocean food web and form massive schools extending for several kilometers horizontally and for hundreds of meters vertically. These schools may increase swimming efficiency and enhance their collective ability to sense prey, predators, or conspecifics. However, the collective behavior of Antarctic krill schools in response to environmental cues such as flow, light, and predator and food odorant levels is not well understood. Working at Palmer Station, Antarctica, we used a novel annular flume capable of generating flow speeds on the order of 1-100 mm s^-1 to investigate how various flow conditions affect krill schooling characteristics. The flume’s inner and outer diameters were 0.3 m and 1.2 m, respectively, creating a 0.45 m wide and 0.13 m deep channel for the school. Flow was generated by rotating the inner cylinder and by submersible pumps positioned along the outer wall and was characterized after experiments using particle image velocimetry (PIV). In these experiments, 700 krill were placed in the tank at a density of 5 krill L^-1 and were subjected to flow speeds of approximately 15 and 30 mm s^-1. Three-dimensional krill positions were measured by an overhead stereophotogrammetry system comprising three cameras filming at 23.7 Hz. Antarctic krill exhibited collective schooling behavior at both flow conditions as they swam against the flow. One minute of footage was processed for each flow condition, and krill swimming speed, school polarity, nearest neighbor distance, and nearest neighbor positions were analyzed. Krill at the higher flow condition swam at higher speeds and at slightly greater distances from their nearest neighbors.