There is no high resolution sonar image for this contact because of a problem in the system start-up process that turned off the recording function.
The target turned out to be a series of flat volcanic shale-like rocks with some exposed sharp and straight edges. These gave the appearance of straight hard returns on the sonar record. They are located just off and adjacent to a long ridge line that was seen on the 600m range scale record. This type of rock will most likely be common in this area and we can expect to see more of this type of target. While we cannot discount everything that looks like this on the sonar record it does give us some experience with how the sonar will image these types of formations.