| Term: | Pack ice |
| Definition: | Any area of sea, river or lake ice other than fast ice, no matter what form it takes or how it is disposed. Pack ice cover may be reported in tenths, or may be described as very open pack ice ( 1/10th to 3/10ths), open pack ice (4/10ths to 6/10ths), close pack ice (7/10ths to 9/10ths), and very close pack ice (practically 10/10ths, with little if any water visible). |