DCHP-1 Online
blue ice 
clear, translucent ice that is compact and solid.
- 1727 (1965) . . . a ship may with as much safety run against a rock as against . . . a hard blue ice.
- 1853 (1884) I have often seen the strength of the Erebus most severely tested between huge dense masses of blue ice, violently grinding past her sides. . . .
- 1956 Brownish or dark ice, it appeared, was dangerous. Blue ice was all right even if it was covered with water. . . .
- 1727 (1965) . . . a ship may with as much safety run against a rock as against . . . a hard blue ice.