Related Clues:

• Navigation hazard
• Titanic's undoing
• Big chip off the old block?
• Variety of lettuce
• Cold mountain?
• Glacier offshoot
• Floating ice mass
• Floating hazard
• Glacial marine threat
• Type of lettuce
• Boston lettuce alternative
• North Atlantic hazard
• Arctic chunk
• Symbol of detachment
• Frozen floater