HomeCalculatorsPOLARIS Risk Index Outcome (RIO)

POLARIS Risk Index Outcome (RIO)

Risk Index Outcome = sum over ice-type fractions × (ice-type-specific Risk Index Value). Per IMO MSC.1/Circ.1519.

PolarPOLARIS

Fraction - open water - Fraction - grey / new first-year - Fraction - thin first-year - Fraction - medium first-year - RIV for open water - RIV for grey - RIV for thin-FY - RIV for medium-FY -

Risk Index Outcome

1.80 -

Operational decision

Normal operation allowed

Formula, assumptions, and limits

Ice-type fractions sum to 1. RIV values per ship's ice-class and ice-type from MSC.1/Circ.1519 Table 1. Negative RIO = restricted operation; master's discretion with mitigation possible between 0 and −10; below −10 generally stop.

Symbol legend

Symbol	Meaning	Unit	Source
	Fraction of each ice type in area	-	ice-chart
	Risk Index Value for ship class + ice type	-	Circular table