KADIO HKOADCASTS AND COMMUNICATIONS 



{a) Having located tlie ice, the patiol vessel will send the follow- 

 ing daily dispatches and radio broadcasts. All dispatches will refer 

 to seventy-fifth meridian time. 



(1) At 0600 seventy-fifth meridian time, and 1800 seventy- 



fifth meridian time, ice information will be sant broad- 

 cast by radio on 600 meters (spark). These broadcasts 

 will be sent three times, with an interval of 2 minutes 

 between each. 



(Note. — It /.s the l/itention to eliminate spark broad- 

 casts as soon as possiUe and all shipping should he so 

 advised in. order that they may equip themselves with 

 receivers capable of CW reception.) 



(2) At 0700 seventy-fifth meridian time, and 1900 seventy- 



fifth meridian time, ice information will be broadcast by 

 radio on 1,621 meters (185 kilocycles) CW. These 

 broadcasts Avill be sent three times, with an interval of 

 2 minutes between each. 



(3) At 2000 seventy-fifth meridian time, a dispatch will be 



sent to the Hydrographic Office, Washington, D. C, de- 

 fining the danger zone, its southern limits, or other 

 definite ice news, and an additional dispatch will be 

 sent during the night if any important information is 

 obtained later. The telegraphic address of the Hydro- 

 graphic Office is " Hydrographic, Washington." To be 

 of value for broadcasting from Annapolis, Arlington, 

 and other shore radio stations, this dispatch must be in 

 the Hydrographic Office before 0900 the following day. 

 (b) Ice information will be given by radio at any time to any ship 

 with which the patrol vessel can comnmnicate. Such information 

 will be furnished as regular radio traffic (without charge) on com- 

 mercial traffic frequencies (wave lengths). 



{c) The following should be observed as closely as possible: 



(1) Use 600-meter wave length (spark) only for broadcasting 



on schedule, calling, answering, and traffic incident 

 to SOS. 



(2) Use conuuei-cial-traffic Avave lengths (except 600 meters 



when possible) for handling traffic other than Govern- 

 ment. 



(3) Use CW transmission whenever practicable (except for 



broadcasting on 600 meters and traffic on 706 meters) 

 and request stations to transmit on CW when known to 

 be so equipped. Reduce to a minimum radio work on 

 spark. 



