The constant struggle with rising sea levels and flood hazards has resulted in the change of the paradigm in shaping urban waterfronts towards increasing their permeability and creation of urban blue spaces. The aim of the paper was to indicate a new approach in designing public spaces at the sea–land interface by presenting a comparative study of the design solutions used in case of the four selected case studies: the Sea Organs in Zadar (Croatia), Norwegian National Opera and Ballet in Oslo (Norway), the Coastal Public Sauna in Helsinki (Finland) and Tel Aviv’s Central Promenade (Israel). The studied examples take into account the permeability of waterfronts (understood as a feature of the edge between water–land consisting of being soft and permeable). The authors decided to use the case study method as the main approach, analyzing such elements as: the site’s location and urban context, features of urban and architectural design (with usage of graphic methods and a qualitative description), and the land–water edge type (defined according the existing typologies). The study proved, that in recent years the designers have started to replace the vertical quay walls, which create a “rigid” water–land border, with multi-level solutions having a high degree of permeability for water.