Beyond a general rule that higher ice concentration requires lower speed, what vessel-specific factors should also inform actual speed selection in given ice conditions?

A. The vessel's actual ice class and structural design capability, current loading/draft (which affects how the hull meets ice), engine/propulsion power margin, and the specific ice type present (multi-year ice requiring far more caution than first-year ice of similar concentration) — a generic concentration-based speed rule is a starting point, not a substitute for judgement informed by the vessel's own specific capability and the actual ice type encountered

B. Vessel loading and draft have no bearing on how a hull interacts with ice, making this an irrelevant factor in speed selection

C. Speed selection in ice depends solely on ice concentration, with no other vessel-specific or ice-type-specific factor relevant

D. Ice class notation has no practical bearing on what speed is safe in a given ice concentration, regardless of the vessel's structural design

A. Once an icebreaker has passed through an area, the channel remains open indefinitely with no risk of re-closing behind it

B. Following distance and channel position have no practical bearing on the difficulty of ice the following vessel will encounter

C. The following vessel should always travel well outside the broken channel to avoid the icebreaker's wash, regardless of the harder ice this involves

D. Maintaining a safe following distance and staying accurately within the broken channel the icebreaker has created, since ice at the channel edges (or ice that has begun to close back in behind the icebreaker) is far more resistant than the freshly broken channel itself — straying from the channel risks the vessel encountering significantly harder, unbroken ice than the icebreaker's passage was calculated to manage

A. Following distance has no meaningful safety trade-off; any distance is equally safe regardless of ice conditions

B. Following too closely risks collision with the icebreaker if it slows or stops suddenly (e.g. encountering a particularly difficult ice ridge), while following too far back risks the broken channel beginning to close in behind the icebreaker before the following vessel reaches that section, exposing it to harder ice than intended — the appropriate distance depends on ice conditions, vessel manoeuvrability, and communication with the icebreaker, not a single fixed rule

C. Following too far back is always safer than following too closely, with no risk of the channel closing in over that distance

D. Following too closely is always safer than following too far back, with no countervailing collision risk to consider