Multibeam data is stored in the "Multibeam" structure for both Fig3 and Fig5. Three different variables are stored. I = acoustic intensity (dB), for Fig3  this is a 2D array and the rows and columns correspond to the Z and X positions. For Fig5 I is a 3D array and the third dimension relates the timestep, with each layer corresponding to a subplot in Fig 5. X = along-flume positions for the acoustic intensity array values, Z = vertical elevations above the flume bed for the acoustic intensity array values. Lidar data is stored in the "Lidar" structure for both Fig3 and Fig5. The data for each of the three Lidars in the Lidar array are stored as Land, Mid and Sea. For each instrument, X = along flume position and Z is the vertical elevation above the flume bed for the Lidar scan  Note that for Fig5, Z has 5 columns with each corresponding to a different timestep as shown in Fig 5.