Marine planners use spatial data to assess planning options. They need analytical approaches, methods, applications and practical software tools to enable assessment of the relationships between human uses and ecosystem components. Here the results of a two-stage process, aimed at developing practical and GIS-based tools for direct use by planners, are presented. First, some available tools for use in the early stages of plan development were reviewed; for example, to identify interaction between activities to reduce potential conflicts or assist in zone delineation, methods to facilitate a risk assessment of the cumulative effect of human pressures and tools offering decision support. Second, a stakeholder workshop was organised to identify routine marine planning tasks and the technical tools required to support those tasks. From the 39 practical tools reviewed, mostly published in peer-reviewed literature between 1998 and 2009, the majority have been applied in the marine environment in Europe, USA and Australia. It was observed that many of the tools are designed to be used by scientists, programmers or strategic planners with only a few that could be used by case officers (regulators). Together with the results of the stakeholder workshop a suite of prototype tools were developed that offer utility to marine planners. Thus the developed tools provide a solid basis for future development as they are a result of a transparent and participatory process.