David S. Greeley
Michael R. Birmann
Fred R. Kern
Atlantic Appl. Res. Corp., 4 A St., Burlington, MA 01803
The Research Vessel/Icebreaker (RVIB) Nathaniel B. Palmer, especially designed and built for Antarctic research and being operated by the National Science Foundation under long-term charter, experienced poor underway performance with most of the installed scientific sonar systems. These sonar problems were diagnosed and remedies designed in May 1993. The approaches used to identify the problems (inadequate sonar windows, bubble sweepdown underway, excessive machinery noise) and the solutions developed to rectify these problems will be presented. Modifications to the Palmer were made in August 1993, and the results of the modifications on sonar performance will be discussed. [Work supported by Antarctic Support Associates/NSF.]