CTD & Friends.
CTD is abbreviated for the name of an instrument package that includes things for measuring the Conductivity, Temperature and Depth of seawater. However it is used for physical and biological oceanography which is made to operate a ship to measure the three variables of the ocean. The information that is gathered during the CTD casts, scientist can investigate the physical paraments that are very similar. I find it very interesting that the CTD can sample so many things other then just in the water, many different things like volcanoes, other deep sea features and even vents.