With a goal of understanding and visualizing the shifting concentrations of movement across the Mediterranean Sea on a centennial basis, the MISAMS (Modeling Inhabited Spaces of the Ancient Mediterranean Sea) Project developed a new GIS-based interpretive methodology that collates and superimposes a series of polygons to model densities of maritime activity in the Mediterranean Sea from the 7th century BC to the 7th century AD. After discussing the project's use of place, space, and maritime landscapes as a theoretical background, this paper explains this new methodology then demonstrates and tests results representing activity in the 1st-century BC western-Mediterranean basin. These results, apparently manifesting distinct socially-constructed places, suggest that this new approach creates new opportunities to understand the movement of people and goods across the Mediterranean in the past, and the varying uses and perceptions of maritime space in antiquity. As this method requires a dense and well-studied corpora of archaeological data, it is theoretically applicable to other maritime regions that have (or will have) the appropriate dataset, and may represent a new research agenda in maritime archaeology.