Emergencies aboard Royal Canadian Navy ships handled by sailors

This video is taken below the waterline on a Harry Dewolf Class Arctic and Offshore patrol vessel. The noise you hear is the sound of the ship breaking ice. At first its very disconcerting as normally when a ship makes such noise it means the ships hitting something or has run aground. Harry DeWolf Class ships have Polar Code 5 Class hull and a Polar Code 4 icebreaking bow allowing it to operate in 120 cm of first year ice with old ice inclusions. It can actually operate in ice thicker than that