In this paper we discuss our digital work and design research on a vulnerable ecosystem, constituted by a landscape that is largely invisible for the unequipped visitor. Within the Bunaken Marine National Park of North-Sulawesi in Indonesia the landscape above the water’s surface – mainland and islands – is deemed to be a minor matter. Contrastingly the main actor, relating to tourism, is the vast underwater world that is visible only for snorkelers and divers. This part of the National Park is most endangered by increasing visitor numbers and related environmental stress – above- and underwater –, affecting the mangrove belts, seagrass meadows, reef flats, reef crests and the vertical reef walls. We argue that it is a necessity to make these sensitive biotopes visible in the form of demonstrative models. We realise that the negative effects of mass tourism are so simultaneously numerous and subtle, that they can only be approached by detailed three-dimensional analysis and design. An understanding of the set of problems faced underwater is key for the design of necessary infrastructure and new forms of management on both water and land. Precise visualisation and modelling not only make sense in this context, they are requisite. While aerial imaging provides the ability to gather spatial data over large areas in short time, which is used to complement more detailed field-based sampling methods. The environmental as well as technological limitations of related underwater reconnaissance in such areas prevail. We centre on two aspects of the described above- and underwater challenge: 1) the experimental assembly of aerial, close-range terrestrial and underwater imageries to create a demonstrative model of the marine landscape, and 2) the corresponding generation of landscape design variants, using the demonstrative model as a baseline. We discuss the limitations and challenges of obtaining a transect model of the marine environment, which includes the complex mangrove structures. These mangroves epitomise the ever-changing conditions in an intertidal ecosystem, illustrating the temporary visibility and invisibility of marine landscape elements over water. Our field-based samples were embedded into a larger digital surface model acquired through aerial photogrammetry to obtain a spatially accurate demonstrative model for our design work. With a comprehensive baseline model, we are able to generate future scenarios and visualise design options.