1. fast ice: sea ice which remains fast, generally in the position where originally formed, and which may attain a considerable thickness. It is found along coasts, where it is attached to the shore, or over shoals, where it may be held in position by islands, grounded icebergs or grounded polar ice. (IHO Dictionary, S-32, 5th Edition, 1772)
  2. glacier: a mass of snow and ice continuously moving from higher to lower ground or, if afloat, continuously spreading. (IHO Dictionary, S-32, 5th Edition, 2041)
  3. polar ice: sea ice that is more than one year old (in contrast to winter ice). The WMO code defines polar ice as any sea ice more than one year old and more than 3 metres thick. (IHO Dictionary, S-32, 5th Edition, 3928)