Breaking Down the Barriers to Acoustic Data Processing: SonarData Echoview Ian R. Higginbottom and Timothy J. Pauly SonarData GPO Box 1387, Hobart, 7001, Australia email: SonarData@verdant.com.au, fax +613 6234 1822 A significant barrier to the wide spread adoption of acoustic methods for stock assessment is the complexity of echosounder and data processing technologies. Analysis of data from the powerful Simrad EK500, for example, has required the scientist to master arcane UNIX operating systems and/or to use inflexible software with poor user interfaces. New software, SonarData Echoview, harnesses the power of the modern PC and the easy to use Windows 95/NT operating systems to provide a powerful, elegant and flexible post-processing (and data logging) package. Echoview provides: zooming and scrolling functions to see data at any level of detail; data quality tools to flag user-defined areas as "bad data", powerful echo integration tools and background noise removal. When logging Simrad EK500s all data analysis functions are available in real time and echograms can be displayed remotely via Ethernet. The key features of Echoview will be demonstrated using data logged from a fishing boat echosounder with a SonarData EchoListener during a project to develop a fisheries dependent acoustic abundance index. The dollar cost (software and hardware), time cost (installation, maintenance, learning) and performance of UNIX workstations and PCs will be compared to demonstrate the advantages of PC based data-processing systems.