The Smart City is an important evolution for cities of different sizes and contexts. Multifaceted proposals are made all around the world. Mobility support and its evolution is an important part of this issue. In this paper we propose to study a particular context, which is devoted to showing how a Coastal city can become a Coastal Smart City. We present our study and proposals based mainly on special mobility configurations, the role and functionalities of corresponding assistive systems, and the HCIs implemented in practice. Finally, we integrate all these aspects in the architecture of the assistive system managing them.