Answer:

icebergs

AnswerCrossword Clue
ICEBERGSSeafaring dangers
ICEBERGSNorth Atlantic hazards
ICEBERGSMostly submerged hazards
ICEBERGSThey're tracked by Canada's Radarsats
ICEBERGSShipping hazards
ICEBERGSFrosty people.
ICEBERGSGlacial phenomena.
ICEBERGSOcean hazards
ICEBERGSThey may come off a shelf
ICEBERGSShipping hazards in the North Atlantic
ICEBERGSPotential ship sinkers
ICEBERGSNorth Atlantic menaces
ICEBERGSGlacier breakaways