ill the critical area, and one vessel collects the oceanographic data 

 and constructs the current maps for the use of the patrol ship. The 

 patrol vessels make cruises of 2 weeks' duration, relieving each 

 other, usually about 100 miles southwest of the tail of the Grand 

 Banks, every fifteenth day. If there is ice well south of 43 degrees 

 nortli or threatening the United States-European lane routes the 

 patrol vessels relieve in the immediate vicinity of the southernmost 

 ice. The commander of the International Ice Patrol force has as his 

 assistant the ice-observation officer, who transfers to the relieving 

 vessel, taking with him his charts and records, and thus remains at 

 sea from the beginning of the patrol to the end, each year. This is 

 done to insure the continuity of the records, to be sure that the actual 

 eye-witness contact with the current ice situation should not be 

 broken, and to eliminate the possible errors and misinterpretations of 

 records incident to the relief of one person by another. The ice- 

 observation officer has two assistants Avho accompany him through- 

 out the season. 



The oceanographic vessel attempts to make one current map per 

 month of the particular area which appears most critical at the 

 time. The senior physical oceanographer of the Coast Guard is 

 aboard this vessel and is in charge of the scientific program of the 

 Ice Patrol. On the oceanographic vessel is a seagoing laboratory 

 in which the sea water salinities and temperatures obtained at various 

 depths are reduced to specific volumes in situ and from these the 

 dynamic heights of the sea surface at the various stations are calcu- 

 lated. The stream lines of the surface currents are drawn, traced, 

 inked, and delivered to the patrol vessel within a very few hours after 

 the last station of the survey has been taken. This construction of an 

 accurate current map, referred to the 1,000-decibar level, and covering 

 an area as large as 50,000 square nautical miles within a period of 

 10 days is a great advance in the field of practical oceanography. 



The patrol vessels for the season of 1935 were the United States 

 Coast Guard cutters Mendota and Pontchartrain. The oceano- 

 graphic vessel was the United States Coast Guard patrol boat General 

 Greene. The commander of the International Ice Patrol was Com- 

 mander E. D. Jones, who was the commanding officer of the Men- 

 dota. The commanding officer of the Pontchartrain was Com- 

 mander E. L. Lucas. On board the General Greene was Boatswain 

 A. L. Cunningham, commanding, and Senior Physical Oceanogra- 

 pher Floyd M. Soule and his two assistants, B. S. Loebig, yeoman, 

 first class, and E. H. McDonald, quartermaster, third class. The ice 

 observation officer was Lt. G. Van A. Graves and his two assistants 

 were R. B. DeGrasse, quartermaster, first class, and J. B. Rice, 

 yeoman, first class, and also Joel S. Wingate, chief quartermaster, 

 during the first part of the patrol. 



