Finnish-Swedish ice class IA Super is assigned to ships capable of navigating in difficult ice conditions without icebreaker assistance.
Ice class IA is assigned to ships capable of navigating in difficult ice conditions, with icebreaker assistance when necessary. Ice class IB is assigned to ships capable of navigating in moderate ice conditions, with icebreaker assistance when necessary. Ice class IC is assigned to ships capable of navigating in light ice conditions, with icebreaker assistance when necessary. Ice class II is assigned to ships that have a steel hull and that are structurally fit for navigation in the open sea and that, despite not being ice-strengthened, are capable of navigating in very light ice conditions with their own propulsion machinery. Ice class III is assigned to ships that do not belong to one of the other ice classes.