# The Usage of Virtual and Augmented Reality in Underwater Archeology
## 5 Use of Augmented and Virtual Reality in Underwater Archeology--Example Solutions
### VISAS Project  
The VISAS project (\"Virtual and augmented exploitation of Submerged Archaeological Sites\") was carried out between 2014 and 2016. It was financed by the Italian Ministry of Education [9,87]. The main goal of the project was to create a system based on VR and AR technologies allowing for the enrichment of the cultural and tourist activities offered in relation to underwater archaeological sites, for scuba divers and non-diving tourists. Thanks to the use of a modern form of communication, the cultural and educational experience could be more engaging for the viewer and could additionally attract new tourists and increase revenues from the tourism industry in a given region [9,117].  
The project was implemented at two underwater archaeological sites. The first of them was Punta Scifo D located on the eastern coast of Calabria, 10 km from Crotone. The underwater site contains underwater artifacts, mainly raw materials and semi-finished marble products that were transported by Roman cargo ships. The site is located at a depth of 7 m [9]. The second site is Cala Minnola; it is located on the eastern coast of the island of Levancz in the Aegadian archipelago, a few kilometers from the western coast of Sicily. The wreck was discovered in 1970. The main element of the underwater archaeological site is the wreck of a Roman cargo ship that was carrying a cargo of amphore with wine. The ship sank around the 1 st century BC and currently lies at a depth of 25 to 30 m [87,118].  
The first stage of the work was to collect data from selected archaeological sites by employing divers and remotely operated underwater vehicles (ROV). The second stage of work included collecting accurate measurements using a multi-beam sonar system mounted on the bottom of the ship from the selected location [9]. The next stage was 3D optoacoustic reconstruction (both visual and acoustic data were used for the reconstruction), from which textured 3D models of underwater archaeological sites were generated. These models were made available to divers and non-diving tourists using VR and AR tools [9]. The VR station is based on five elements: a database, a website, a scene editor module, an interaction module, and a controller. The Unity system was used to create appropriate modules [119].  
In this case, VR allows users not only to view underwater archaeological sites and acquaint themselves with their 3D reconstructions, but also to receive information about specific sites in the historical context and information about submerged exhibits [117]. The application also included information about local flora and fauna, with a particular emphasis on their impact on submerged artifacts [9,118]. As an additional benefit for the divers who will use the system, it may be used as an underwater route planning tool [37]. VR can be explored both using a stand with an HD monitor (Figure 5a), as well as using a VR set, e.g., \"VIVE HTC\" [119].  
AR was implemented in the project using an underwater tablet equipped with a positioning and orientation system--Figure 5b [9]. The positioning and orientation system operates using an acoustic modem and stationary transmitters placed on the seabed (LBL--Long Base Line technique). The tablet was also equipped with an inertial platform, and a depth sensor guides divers during a diving session, and at the same time provides information about the archaeological artifacts found [9,87].  
It is worth noting that the virtual application, apart from archaeological education, can also be used by archaeological divers to plan dives at archaeological sites. It allows for the planning of work, taking into account field conditions and changing environmental conditions, e.g., water transparency [87].