Ten C-PODs (Continuous Porpoise Detectors ; Chelonia Ltd., UK; http://www.chelonia.co.uk/) and 2 PCLs (Porpoise Click Logger or AquaClick 100, Aquatec group Ltd., UK; http://www.aquatecgroup.com ) were suspended from the pool floor. Two cameras recorded the behaviour of the dolphins for 12 hours a day. A roof camera documented the swimming patterns and an underwater camera documented the interactions with some of the loggers.