The magnetometer data were acquired by Wessex Archaeology using a Geometrics G882 caesium vapour marine magnetometer over two seasons, 2009 and 2012. The magnetometer data were processed using Geometrics MagPick software in order to identify any discrete magnetic contacts which could represent buried metallic debris or structures such as wrecks. All anomalies identified have magnetic amplitudes above 5nT.
The two surveys resulted in a total of 71 anomalies that were identified as discrete, probable archaeological targets (See Figure). 51 of these targets are in the northern section of the site, and are thought to be related to wartime (WW1 and WW2) armament practice. There are records of gun practice across the Dingle and Dunwich marshes that may explain some of the anomalies. In WWII, metal 'dragons teeth' were embedded along the coastline, which may also explain some of the near shore anomalies in the north of the site.
The other clusters of sites surround the central part of the town around St Peter's church and the market place (central area), and St Nicholas Church / Blackfriars site (southern area). Military Ordnance has been found across the St Peter's Church site.