Figure 2. The instrumentation buoy used to collect behavioral data from cod in the offshore net pens. The buoy was modified from a coast guard navigational buoy. One waterproof tube (B) was used to hold a rack of four 12 VDC batteries. Two students are shown loading them into the battery tube in the far right picture. Solar panels and a wind generator provided additional power. The other waterproof tube (A) in the buoy was used to hold the instrumentation (computer, HTI receiver for tracking, DVR for video). A box (C) was mounted on the top of the buoy to serve as a type of switchbox for all the cables leading from the buoy to the cage, located ~50-100 ft. under the surface.