This Atlantic ice chart is sent by CFH, Canadian Forces Halifax, daily at 0001 UTC. After the RMS Titanic sank in these waters, ice reports became serious business. They still are.
"Bergy bits" are small icebergs rising 1-4 meters out of the water. They are hard to spot. "Growlers" are even smaller, rising a meter or less, and even harder to spot. They tend to be flat, and often in later stages of melting. Escaping air causes the "growl."
All fax signals are tuned 1.9 kHz lower than their listed frequencies.