The Norsk Øy Ice Barrier (NØIB) is a region of fast ice that is located off the north-east coast of Greenland. It is one of the most extensive areas of landfast ice anywhere on Earth. In the past the NØIB survived the summer melt, but in recent years summer break-ups have become more common. This study looks at the NØIB formation during the freeze-up of late 2003 and the total break-up in the subsequent summer (2004). As the fast ice is immobile it provides an ideal location for checking the consistency of classification schemes for satellite sensors. Active microwave (SAR) backscatter values from Envisat and Radarsat-1 are compared with optical observations from MODIS, multi-channel passive microwave from AMSR-E and SSM/I, with ice freeboard values from the Envisat RA-2 radar altimeter, and the analysis found in Norwegian ice charts. In August 2004 the underside of the NØIB was mapped by a multibeam sonar mounted on the Autosub AUV. Statistics from sea-ice draft measurements by the multibeam are compared with near coincident satellite observations. Evaluating the evolution of the fast ice through multiple satellite sensors with ground truth measurements will allow future development of improved automatic classification algorithms which will be better able to track fast-ice extent. Loss of the fast ice for periods of the year has implications for the coastal environment of Greenland and may be a contributory factor in the retreat of the Nioghalvfjerdsfjorden Glacier and enhanced coastal erosion.