Polar Code - Safe Speed in Ice
Recommended safe speed in ice per POLARIS / IMO MSC.1/Circ.1519 - speed reduced from open-water speed as RIO score approaches zero.
POLARIS risk class
normal
Recommended max speed
14.0kn
Formula, assumptions, and limits
RIO ≥ 0: operation normal. -10 ≤ RIO < 0: elevated risk, reduce speed (typ. ≤ 8 kn). RIO < -10: operation not recommended. Actual ice class RIV values from MSC.1/Circ.1519.
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| Risk Index Outcome | - | MSC.1/Circ.1519 | |
| Ice concentration of type i | tenths | ice chart | |
| Risk Index Value | - | MSC.1/Circ.1519 Table 1 |