The processing on board was mainly aimed at (a) verifying the positioning data of the tow-fish, and (b) picking the phase wraps (swath bathymetry) from the TOBI data. Once magneto-otical cartridges were filled, they were immediately copied onto CD-ROM, which could then be ported to the SUN WS for merging with navigation data. The merged files were then used for pre-processing of TOBI images. The navigation data were used to produce navigation maps which were then used as base-maps for mosaicking printouts of the sidescan sonar images by hand (for preliminary interpretation aboard ship).