Inspecting & Documenting Archaeological Sites
Diving and identifying a site found during previous survey operations
Diving the site for the first time
Following remote sensing surveys, verification dives are planned. These will confirm what type of remains have been discovered and provide first-hand impressions of the composition, size and state of preservation of the site.
Surface team (2019) by University of MaltaUniversity of Malta, Department of Classics & Archaeology
A common feature of underwater heritage sites in Malta is depth, with the majority located below the 50m contour line
Diving configuration (2019) by University of MaltaUniversity of Malta, Department of Classics & Archaeology
For sites up to a depth of 130m rebreather technology is used by divers, allowing for longer dives.
Divers at deco station (2019) by University of MaltaUniversity of Malta, Department of Classics & Archaeology
The deeper a diver descends and the longer time spent at depth, the more challenging the dive becomes. Longer in-water decompression is a distinct feature of these deep dives.
ROV (2019) by University of MaltaUniversity of Malta, Department of Classics & Archaeology
Sites that are discovered beyond the diving limit are explored and recorded through footage and photographs generated by a Remote Operated Vehicle (ROV).
Inspecting the wreck (2020) by University of MaltaUniversity of Malta, Department of Classics & Archaeology
Direct contact with a site allows specialists to gain first-hand impressions of what has been found on the seabed. These inspections also help determine whether conducting 3D surveys is an option.
3D documentation
Planning a 3D underwater survey is not straightforward and requires that all necessary equipment is available and functioning. This is true for both the equipment needed to safely perform these challenging dives and the equipment needed for the photogrammetric survey.
Documenting the site (2020) by University of MaltaUniversity of Malta, Department of Classics & Archaeology
Using a full frame camera, photographs and video footage are shot and utilised to create accurate and scaled 3D models.
Adapting to each site
The digital 3D models are created from sets of overlapping photographs. Depending on the size and complexity of the wreck and on the visibility of the water, many hundreds, if not thousands, of photographs are required
Lights for the documentation (2020) by University of MaltaUniversity of Malta, Department of Classics & Archaeology
Besides using the high-resolution mirrorless cameras protected in waterproof housings, strong lighting is essential to light up the wrecks and to capture the colours present on these sites.
Creating the 3D models
The process of documentation entails that every angle and detail must be photographed and recorded. Once the photographs are taken, they are loaded into a powerful computer and processed in a highly specialised software. Through a process called photogrammetry, the images are converted from a set of overlapping photographs into 3D models.
Using 3D to monitor (2019) by University of MaltaUniversity of Malta, Department of Classics & Archaeology
3D models serve as baselines from which the preservation and condition of underwater sites can be monitored. This is applicable both in terms of the cultural and natural heritage found on the site.
The importance of the object (2019) by University of MaltaUniversity of Malta, Department of Classics & Archaeology
Sometimes, a decision is taken to recover objects from the archaeological sites being explored, due to the importance of the object, or the risk of it disappearing.
Hand held scanner (2020) by University of MaltaUniversity of Malta, Department of Classics & Archaeology
A portable hand-held scanner is used to digitise various cultural objects from an underwater context.
Object documentation (2020) by University of MaltaUniversity of Malta, Department of Classics & Archaeology
This method helps to generate accurate documentation in a rapid way, which allows the teams to start studying the objects as soon as they reach the lab.
Photography, 3D models & documentation: University of Malta, Heritage Malta, K. Goovaerts, D. Gration, K. Hyttinen, G. M. Iaria & J. Wood.
Special thanks to everyone who participated in this project and made it possible.
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