Navigating in ICE 

Ice navigation is a specialist area of navigation involving the use of maritime skills to determine and monitor the position of ships in cold waters.
When navigating in ice, the general rules are: use the pack to its best advantage. Follow open water patches and lighter ice areas even if initially it involves large deviations of course. in limited visibility, beware following an open water lead at excessive speed, it may be the trail of an iceberg.
International Code for Ships Operating in Polar Waters