An EdgeTech 2200-M Hosted Platform Side Scan Sonar is mounted “upside down” on the sail of a US Navy Nuclear Submarine. When the submarine goes under the polar ice the “ice pilots” use the side scan sonar to image the underside of the ice pack. They look for gaps in the ice where there is open water. This provides them with a location where the submarine can surface should that become necessary. The side scan sonar provides a historical record and location of these gaps so that they can go back to an opening.