A global trend in declining island populations is causing severe accessibility challenges for rural archipelago residents. Since waterways often provide the only viable connection between islands, the planning of ferry routes and capacities relative to prevailing population patterns is critical. In this paper, we present a case study of Pargas, a rural archipelago region in Southwestern Finland, which in many ways provides a typical example of current depopulation trends in archipelago regions. Owing to high maintenance costs, changing population patterns and transportation needs, the ferry network of Pargas has recently attracted attention in terms of planning and a perceived need to reduce costs. Still, compared to in-land transportation, few academic studies have explored this issue. Using methods adapted from urban and land-based transport studies and diverse datasets, we aim at identifying spatial discrepancies between population patterns and transport options in the peripheral archipelago and at determining how well the ferry network meets the needs of the permanent and seasonal population of the islands. Our results show that although the existing ferry network in general functions relatively well in relation to the population, spatial mismatches between transport opportunities and population patterns in some of the prominent islands are nevertheless evident. Because the economic vitality of the region depends on a well-functioning transportation network, this study offers suggestions for improving transportation services in the study area.