|A thin elastic crust of ice, easily bending on waves and swell and under pressure, thrusting in a pattern of interlocking 'fingers' (finger rafting). Has a matt surface and is up to 10cm in thickness. May be subdivided into dark nilas and light nilas. Dark nilas is 5cm thick and very dark in colour. Light nilas is 5-10cm thick and reflects proportionately more light than dark nilas, depending on its thickness.