Cleaning the optics on a profiling arm

A science collaborator, working with the USGS, cleans the optics on the profiling arm before deployment south of Martha's Vineyard (in background). Some of the instruments visible here are a laser-diffraction particle sizer (labeled "LISST-100X"), CTD (at end of arm, with copper tape to prevent fouling), white acoustic Doppler velocimeter (left of CTD), multiwavelength optical backscatter sensor (being cleaned), 10-cm transmissometer (on top, with some blue antifouling paint), and screened water intake (right of CTD). Cable to an accelerometer hidden behind the CTD is marked with red tape.