The Society of Naval Architects and Marine Engineers Panel M -16 (Modernization of Propulsion Shaft Systems) held its 1st. meeting June 21, 1960. Various problem areas were discussed but the one area believed to be of major concern to this industry was stern tube bearing wear. Life of the after stern tube bearing was known to be very short on certain large tankers. In order to determine the extent of this problem throughout the marine industry and at the same time obtain certain information that might provide a guide to the cause of the problem, if the problem was found to exist, a questionnaire was sent to about 33 American dry cargo, ore carrier, and tanker operators. Almost 100% response was received. Data on stern tube wear of some 263 ships were obtained. This report is a summary of this data.