At the beginning of this month Wessex Archaeology divers were back on the Thames Estuary to investigate a geophysical anomaly that was thought likely to be the paddle steamer Royal Adelaide.

The paddle steamer Royal Adelaide was lost on Tongue Sand off Margate, Kent in 1850 during a gale whilst carrying about 250 passengers, livestock and a general cargo from Dublin to London. Many were likely to have been very poor Irish people fleeing the continuing impact of the Great Hunger of 1845-9. Everyone onboard was lost.

The diver inspection followed a geophysical survey that was undertaken in 2019 and identified the site as a potential candidate for the Royal Adelaide.

Paolo diving

Diving in the Thames can be a challenging task. Poor visibility and only limited bottom time due to strong currents mean that the work is done mainly by touch and that every minute on site is precious.

Fortunately, technology can help, and our divers deployed a handheld high resolution imaging sonar which assisted them to navigate, surveying and recording the wreck. A stream of video-like sonar imagery is fed to the supervisor on the surface helping him to direct the diver to the areas for inspection. Systematical sonar sweeps also meant that we were able to acoustically map large portion of the site more quickly and effectively.

It took just two dives to our divers to confirm that the remains scattered over the location did not belong to the Royal Adelaide but were more likely to be part of a largely dispersed more modern iron riveted vessel. The diver found several disconnected sections of hull lying onto the seabed and identified what appeared to be a section of the stem lying upside down at some distance away from the main area of the wreckage.


Once it became clear that the wreck was not the Royal Adelaide and of limited archaeological significance the team quickly redeployed to check a nearby anomaly that had been flagged as potential archaeology during the 2019 geophysical survey.

The archaeologist dived the anomaly location and confirmed the presence of a large, rounded structure covered in marine growth. The object was rather featureless but the magnet stuck to it meaning that it was likely to be made of ferrous material. It was not clear what this feature might be until a second anomaly was picked during a sonar sweep approximately 30 m away.

The diver travelled to inspect this new anomaly and identified it as a mooring block with a chain. The association with the round structure that had been just visited was quickly done; it was an old navigational buoy.

Large, rounded feature on the scour in front of the diver The mooring block at the centre of the image with the chain delineating the long arc to the left

Left: Large, rounded feature on the scour in front of the diver

Right: The mooring block at the centre of the image with the chain delineating the long arc to the left

Unfortunately, this time our investigation in the Thames did not result in the discovery of a great new site, unlike our previous investigations. Nonetheless we now have work to do in the archives to try and identify this new wreck and the search for the Royal Adelaide continues.

By Paolo Croce, Marine Archaeologist