outlay could be avoided merely by rounding the southern limits of 

 field ice. The position of the field ice tongue on May 1 is graphically 

 shown on the cruise chart for the fourth cruise. (See fig. 12.) 



It is desired to point out that no two seasons are alike with regard 

 to the position, amount and compactness of field ice. Apparently 

 the masters of the vessels that stood into the ice along tracks E and 

 to northward had been able to accomplish a safe passage at tliis 

 time of year during previous seasons and did not realize the risks they 

 were taking. The position and amount of this ice varies not only 

 from season to season but from month to month and from day to day. 

 Therefore, steamers should copy the broadcasts as early as possible 

 and plot their courses in accordance with the latest information. 



Frequently during the latter part of the season cumulus clouds on 

 the horizon are found at twilight to closely resemble large bergs. 

 This is experienced more generally in the southern portion of the 

 area. Even the ice observation party, on occasion, have been in 

 doubt and forced to wait until the clouds either ascended above the 

 horizon, disappeared, or became so large as to definitely indicate that 

 they were not bergs. 



Most of the steamers using routes that pass through the Ice Patrol 

 area are familiar with the information desired from them by the Ice 

 Patrol; i.e., all ice sighted, and when between latitudes 39° and 49° 

 N., and longitudes 43° and 56° W., sea-water temperature, barometric 

 pressure, weather, visibility, position, course, and speed every 4 hours. 

 When the ice broadcasts became lengthy, the request for this informa- 

 tion was shortened to the following words: "Vessels are requested to 

 make the usual reports every 4 hours." In order that a fuller appre- 

 ciation of the necessity for these reports may be had it is desirable 

 to discuss their use by the patrol vessel. 



Reports of position, course, speed, and visibility serve two pur- 

 poses. First, they enable the patrol to issue a warning in the event a 

 steamer is unknowingly standing into danger. Second, when a ship 

 passes through an area in clear weather and ice previously reported 

 along its track is not sighted, that ice can be stricken from the broad- 

 casts, the broadcasts thus become more accurate, are kept to a mini- 

 mum length, and the patrol vessel has better knowledge of existing 

 conditions. The latter is especially helpful to the patrol force after 

 long periods of fog during which no scouting could be accomplished. 

 The sea temperature reports are used in plotting the isotherms on the 

 cruise chart thus defining the boundaries of the cold Labrador water, 

 the Atlantic Current, and the transition zone between these two 

 currents. Bergs are more likely to be found in the Labrador Current 

 and transition zone. (It is not desired to give the false impression 

 that icebergs may be found only in cold water.) The Coast Guard 



