Underwater photogrammetric monitoring techniques for mid-depth shipwrecks

Abstract

Abstract Over the last few years there have been advances in technical diving, which have made it more accessible (including financially), making it possible to dive to greater depths and, consequently, reach underwater archaeological sites in deeper waters, which were previously considered “untouchable”. As these sites are now at potential risk of anthropic interference, new approaches to monitoring techniques are therefore considered necessary to ensure the protection of Underwater Cultural Heritage. This paper presents a protocol for monitoring techniques to be applied to ‘mid-depth archaeological remains’. The proposed technique is based on a combination of low-cost photogrammetric methods. Using as a case study a Roman era shipwreck from Majorca, off the east coast of Spain, this paper presents an ideal protocol for the essential first stages in protecting and managing the archaeological record of an underwater site at medium depth. The process gives immediate results, using photogrammetric and orthophoto coverage of the site to build up a highly accurate site map, as well as recording high-definition images in order to create a computer model of the site.