This licentiate thesis investigates the use of digital visualisations for knowledge production and communication of maritime heritage located underwater. The archaeological practice that takes place in response to development, contract archaeology, is the field that is being investigated. Much of the practical and administrative aspects of contract maritime work involves the survey, excavation and interpretation of archaeological remains. In addition, shifts in heritage policy emphasise that the results of this work move beyond their own value to provide access and democratic participation to heritage and be of benefit to society (e.g. Faro Convention, 2005). Since the inaccessibility of maritime archaeology underwater makes outreach especially challenging, digital, and in particular 3D, technologies have been recognised as having great potential to meet the needs of both maritime archaeological researchers and public audiences. Advances in methodologies for digitally documenting and visualising archaeological sites, both on land and underwater, are providing a range of innovative and multidisciplinary solutions for both archaeological analysis and outreach activities. The aim of this research is to understand current uses of digital visualisation for knowledge production and communication of maritime archaeology located underwater, in order to identify knowledge gaps that would benefit from future research. This aim is met through a study drawn primarily from the fields of digital archaeology, maritime archaeology and heritage studies, as well as discourse and thematic analysis of the factors that influence the use of these technologies in the sector. The case study is the contract maritime archaeology sector in Scandinavia, with a primary focus on the practice in Sweden and also including perspectives from the Danish and Norwegian sectors. The results show that an emphasis on efficiency within the contract sector shapes the understanding and use of digital technologies, in some instances limiting their potential for archaeological interpretation and communication. While the maritime sector was found to be partly defined and restricted by a distinct identity, at times operating independently from mainstream archaeology, it was also found to be open to innovation. This represents great potential for digital workflows aimed at enhancing both interpretation and communication to be applied to the maritime archaeological sector in the future.