Multi-year ice is the hardest sea ice and should be avoided if possible. It is recognizable because of what tone to its surface color?

Correct Answer: Option A — Bluish

Multi-year ice has undergone several melt seasons, leaching out brine and causing the internal crystal structure to transform. This process eliminates air pockets, turning the ice a distinctive bluish color, indicating high density, extreme hardness, and maximum resistance to vessel navigation.