This article introduces the concept of ‘Sea Cities’ to emphasize a range of tactics to acknowledge the relationship between the sea and cities. This concept is critical for the possibility of integrating future aquatic-based urbanism to address climate change, and in particular, the issue of rising sea levels, which is currently faced by the majority of coastal cities. We compare and assess the tactics of four sea cities (i.e., to fortify, accommodate, release, and floating) against the case study of Jakarta. Jakarta is deemed to be among the metropolitan cities most vulnerable to sea level rise, owing to overpopulation alongside the fact that its land is sinking rapidly due to massive urban development. In order to understand the prospects and pitfalls of each tactic for Jakarta, we analyse scholarly literature on the subject, official government reports and documents, as well as policy briefs released by governments at the national level. This study finds that massive hard structural solutions are not only insufficient but also ineffective towards solving the challenges of climate change in Jakarta, especially the rising sea level. At the same time, it also identifies that while the combination of accommodating and floating tactics has never been considered as future a planning option, this could enable more resilient and adaptive solutions for the future development trajectory of Jakarta. In doing so, it could also provide important transferrable lessons for other coastal cities, especially those within developing countries.