The BlueHealth Toolbox is for planners, designers and other decision-makers responsible for blue spaces. The tools provide the means to make comparable assessments of urban blue spaces before and after any proposed changes. Such changes can include a wide range of interventions, from physical alterations to the environment to advertising campaigns that influence how people interact with it. The tools provide evidence about the quality of blue environments, as well as information about how people and communities use, perceive and interact with blue spaces. They also assess the state of people’s health and wellbeing. Together, this evidence can enhance urban planning and design.