NIK is the callsign used for International Ice Patrol charts broadcast by US Coast Guard from NMF, Boston during the late winter/ spring ice season. The faxes originate at Communications Area Master Station, Atlantic (Camslant). Boston is therefore a remote transmitter in this case.
After the RMS Titanic had its infamous encounter with an iceberg in April, spotting North Atlantic ice became a very serious business. Ice charts are broken down into grid squares, and show the number and type of bergs in squares having them.
All fax signals are tuned 1.9 kHz lower than their listed frequencies.