ABSTRACT Citizen Science (CS) strengthens the relationship between society and science through education and engagement, with win-win benefits. Marine Citizen Science (MCS) is increasingly popular, thanks to society’s growing interest in marine environments and marine issues. Scuba diving significantly increases the potential of MCS, thanks to the skills and behavioural properties of people who participate in the sport. To be able to exploit this potential, however, MCS needs to face challenges related to CS, to scuba diving activities and to the broader scuba diving industry. In particular, engagement and recruitment of potential volunteers, as well as retention of active participants, represent key milestones. In order to reach these milestones, information is required on current participation levels of scuba divers in MCS, as well as the motivations behind participation, and the opinions held by potential participants in MCS. This study explored different case studies and methods of data collection to provide an overview of actual and potential participation in MCS by the scuba diving community. The results show that scuba divers, whether active or potential marine citizen scientists, are well disposed towards MCS. Some barriers, however, prevent the full participation of scuba divers as marine citizen scientists. Certain barriers extend beyond the control of both divers and MCS projects, while others, such as limited access to MCS projects and poor feedback after participation, can and should be addressed. The recommendations of this research provide strategic direction to MCS, so that the broad scuba diving community can be successfully integrated into MCS. These recommendations acknowledge the important role played by stakeholders in the scuba diving industry, as well as professional intermediaries and hired experts. This paper has received funding from the European Union (EU)'s H2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 643712 to the project Green Bubbles RISE for sustainable diving (Green Bubbles). This paper reflects only the authors' view. The Research Executive Agency is not responsible for any use that may be made of the information it contains. © 2018 Lucrezi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.