Horizontal movement data and accelerations collected from a single horn shark at Santa Catalina Island, California, USA

2 sources of data were collected from a single horn shark (Heterodontus francisci) at Santa Catalina Island, California, USA, over a period of 24 hours in June 2017: geopositional and acceleration data. Custom tag packages were externally attached to the dorsal fin of the shark that included an accelerometer data logger (Technosmart, AxyDepth) and an acoustic transmitter (Vemco V9 continuous pulse pinger, 2000 milliseconds). The shark was actively tracked from a tracking vessel above using a Vemco VR100 on-board receiver and VH110 directional hydrophone. During active tracking, geopositions were estimated for the tracking vessel relative to that of the tagged shark. Although boat position was recorded every 2 seconds, position data were filtered according to the closest possible estimations of the shark to the boat. Geopositional error for the shark was estimated to be 5 metres (via range tests at the study location). To characterise the shark's horizontal movements, we processed the geopositions into step lengths by calculating the Euclidean distances between consecutive geopositions. Acceleration data were recorded continuously at 25 hertz in 3 orthogonal dimensions, the dorso-ventral, anterior-posterior, and lateral axes. We summarised the acceleration signal across the 3 dimensions by calculating the overall dynamic body acceleration. The workspace contains 2 lists, entitled steps (containing the step lengths) and odbas (containing the accelerations).