Figure A-3. Oceanc^raphlc-hydrograpliic winch. 



continuous data on water temperature, salinity, 

 or conductivity. Seismic and acoustic measure- 

 ments are made with two ships — one lying-to 

 and the other underway. 



The greater portion of oceanographic work 

 at sea is carried out while occupying an oceano- 

 graphic station in which the ship is lying-to. An 

 oceanographic station is any group of oceano- 

 graphic observations made at the same, or 

 virtually the same, geographic position at nearly 

 the same time. An oceanographic station most 

 commonly comprises a group of observations 

 such as Nansen casts, bottom sediment sam- 

 plings, bathythermograph lowerings, and asso- 

 ciated observations made at one location. One of 

 the primary objectives of occupying an ocean- 

 ographic station is to determine the temperature 

 and salinity of the water at various depths in 

 the ocean. 



In planning an oceanographic cruise, ocean- 

 ographers plot the locations where informa- 



tion is to be sought on a station location chart. 

 It is the responsibility of the oceanographer in 

 charge of the cruise to insure that me proper 

 thermometers are supplied to observe the tem- 

 peratures in the desired working area. He can 

 accomplish this purpose by studying the water 

 masses of the area in material already pub- 

 lished. He also must insure that the ship has all 

 the necessary equipment and accessories for 

 properly conducting assigned observations dur- 

 ing the cruise. 



A-14 Occupying an Oceanographic Sta- 

 tion. — The instruments and equipment to be 

 used are put in readiness before arriving on 

 station. When the navigator has determined 

 that the ship is at the desired location, the ship 

 is maneuvered so that the winch to be used is to 

 windward. (In this position the ship will usually 

 drift away from the cable that is suspended in 

 the water.) The ship's engines then are stopped. 



A-5 



