# The VIRTUALDiver Project. Making Greece's Underwater Cultural Heritage Accessible to the Public
## 1 Introduction  
The underwater environment in Greece is of great scientific interest in all fields of marine research. However, it has not yet been sufficiently exploited for cultural and tourism purposes. At the same time, technological advantages in the fields of Virtual (VR) and Augmented Reality (AR) have undergone considerable development by providing technical solutions for environments that their modeling has been problematic or non-operational in the past. From medical training to gaming, these technologies provide a variety of prospects that can lead previously designed and applied schemes to new directions and help new ideas to arise and develop. Especially in the area of cultural management, creating digital narratives accessible not only to the experts but also and, most importantly, to the general public in an intriguing and scientifically accurate way is of great significance [1; 2; 3; 4; 5; 6]. What makes the narration in a virtual or augmented environment special is the feeling that the user is \"living\" the experience, allowing the narrative to be perceived through different perspectives or characters (avatars), while the \"immersion\" stimulates more emotional involvement. That is why for the past decade a number of relevant projects have been running towards successful cultural implementations [7]. The Underwater Cultural Heritage (UCH)--a substantial cultural capital that lies on the seabed of the world--is an important resource that needs to be protected and valued. It also stands as a triggering factor for touristic development, concerning especially underwater archaeological sites, be they shipwrecks or submerged landscapes, highly fascinating for the public, both for the sense of mystery that surrounds them and the symbiosis between artifacts and sea life. Access to these sites is limited, as only a small percentage of people can actually dive or due to the fact that a great number of these sites are in depths beyond human reach. Digital technologies (e.g., Virtual Museums, Virtual Guides, and Virtual Reconstruction of Cultural Heritage, Augmented Reality applications) provide a unique opportunity for digital accessibility to both scholars and the general public, interested in having a broader perception of these underwater sites [8; 9; 10; 11]. Some representative cases of applying VR and AR technologies in the promotion of UCH are shown here in order to place the framework of the VIRTUALDiver project. Project VISAS: Virtual and Augmented Exploitation of submerged Archaeological Sites, is a collaborative research project created to improve the responsible and sustainable exploitation of underwater archaeological sites by reconstructing the underwater terrain, creating a VR system for exploring this environment, and making a virtual guide experience for mobile devices used underwater [12; 13]. Researchers of the project i-MARECULTURE integrated digital technologies to promote UCH to the public [14]. They developed a VR system that allows users to experience underwater environments with high cultural value, using gamification methods to create two serious games that explained the underwater excavation methods. Additionally, in order to improve underwater cultural tourism, they developed a waterproof AR system capable of acting as a guide of specific underwater archaeological sites. Other projects with similar research focus are the Lab4 Dive [15; 16] and the VENUS project [17; 18], both of which are scientific platforms that facilitate underwater research and, ultimately, communicate UCH to other scientists and the public. Apart from the above academic research, projects from the private sector are also worth mentioning. The Blu: Deep Rescue is a virtual underwater experience giving the participants the opportunity to swim together with sea creatures like turtles, sharks and whales [19].