A Geophysical Debris Survey of the Wreck 80 site off the South West corner of Plymouth Breakwater

Modern advents in survey techniques and technology have enabled the field of marine archaeology to improve dramatically over the past 60 years. The use of geophysical methods, both acoustic and non-acoustic, has allowed archaeologists to locate and study areas previously inaccessible. The maritime history of Plymouth Sounds extends into the past over 700 years and is home to an indefinite amount of shipwrecks from both merchant and naval. Many of these wrecks are known and well documented, however there are a significant number of which very little are known. This provides a huge scope for potential projects, such as this one, to highlight areas of archaeological interest and create an informative background knowledge to improve further investigations. The survey aimed to identify and locate any surface and magnetic targets surrounding the known wreck site. No one technique can provide all the necessary information required. This study demonstrates how the use of different techniques complement each other when locating targets. The processed multibeam data provided excellent depth contours with clear images of underwater features. The backscatter data provided useful information regarding the geology of the sea floor and the magnetometer provided a number of very clear magnetic anomalies within the survey area, some visible on the seafloor, some not. It is very rare that a survey will be undertaken free of any problems, whether human or natural, and this study is no exception. The results do however provide excellent scope for further investigation of the site due to the presence of some extremely clear surface and magnetic targets