(NIK), accepts ice reports and at all times accepts traffic for NIDK 

 should a vessel be heard calling and unable to establish communica- 

 tion with the patrol cutter. Ice information is disseminated by 

 means of regularly scheduled NIK ice bulletins. Occasional safety 

 (TTT) broadcasts are made upon receipt of the information in cases 

 where ice is discovered in a position of unusual hazard and especially 

 if the ice patrol vessel (NIDK) is guarding a berg that has drifted 

 into or is about to drift into a steamer lane. 



Ice patrol activities generally start with the opening of the ice 

 patrol office at Argentia in February and the commencement of aerial 

 reconnaissance. Wlien ice is present in sufficient quantity or when 

 the advancing season would lead mariners to expect ice and make 

 radio inquiries regarding ice conditions, the series of twice-daily NIK 

 ice bulletin broadcasts is initiated. When the ice situation warrants, 

 a continuous surface patrol is inaugurated and the inauguration is 

 formally announced in the NIK ice bulletin broadcast. In the Grand 

 Banks area, visibility deteriorates with the advancing season and 

 during a light ice year or one when the ice is late in arriving and 

 under conditions when continued poor visibility prevents the ice 

 patrol office from following the ice situation w^ith sufficient continuity 

 by means of aerial reconnaissance, surface craft are emplo3^ed for ice 

 observation. A distinction is made between ice observation and ice 

 patrol. Ice Patrol is a continuous surface-vessel patrol.. Ice observa- 

 tion cruises may be intermittent or continuous as required to supple- 

 ment aerial reconnaissance in determining when a continuous patrol 

 may become necessary. Trained ice observers from the ice patrol 

 office participate in the aerial reconnaissance flights, and, whenever 

 possible, a trained ice observer is assigned to the cutters on ice- 

 observation cruises and ice patrol. "V\^ien the series of ice bulletin 

 broadcasts is inaugurated, mariners are requested to furnish NIK 

 or NIDK four-hourly reports when they are in the area bounded by 

 latitudes 39° N., and 49° N., and longitudes 43° W., and 54° W. 

 These reports should contain the position, course, speed, water and 

 air temperatures, "visibility, wind and sea conditions, and any ice 

 sighted. These four-hourly reports are collected by the ice patrol 

 office and the cutters until the end of the season. They form the 

 basis of ship plots and surface isotherm plots, aid in the evaluation 

 of fl.ying weather in the Grand Banks area and materially assist in 

 determining the movement and disintegration of ice. 



For the 1950 season Capt. John A. Glynn, USCG w^as Commander, 

 International Ice Patrol. Lt. Comdr. Edwin C. Crosby, USCG w^as 

 the senior aviator in charge of the ice patrol aircraft. Ice patrol 

 cruises were made by the Acushnet commanded by Capt. Frank K. 

 Johnson, USCG and the TamjM commanded by Comdr. Howard 

 A. Morrison, USCG. Oceanographic cruises were made by the Ever- 

 green under the command of Lt. Comdr. Gordon P. Hammond, USCG. 



