This research is about the factors that make transport over water economically feasible for a city. The two sub questions are: “Does the number of landing points and the length of the network of transport over water influence the economic viability of the project?” and “What are the costs and benefits for the Stadsregio Rotterdam”. The thesis starts with an introduction of the topic, followed by a literature review of success factors about new modes of public transport (chapter 1 and 2). The thesis then continues with a chapter about Rotterdam, with a description of the current situation of the public transport in Rotterdam and the goals of Rotterdam written in 2 independent reports (Stadsvisie Rotterdam and RVVP). The fourth chapter is about the relative “new” form of public transport that was supposed to be introduced in Rotterdam, which is the public transport over water. This chapter also talks about the estimated costs and incomes that the introduction of a new mode of public transport has. Calculations will be made about the break-even point and the estimated surplus/deficit for the provider of this public transport over water. In other words: “How many people have to make use of the public transport over water to cover the costs” and “What is the balance between income and costs each year”. This chapter also contains a cost-benefit analyses to try and help us make the decision if public transport over water has enough advantages for the city to introduce it. Chapter 5 is the last chapter and contains the conclusions. Public transport over water is a mode of transport that needs a lot of subsidy to be financially sustainable. The more stopping points there are the more expensive it will get. Public transport should also be seen as an addition to the public transport network, but shouldn’t be the only mode of transport. This has to do with the area it can supply with public transport is bounded by the river (and doesn’t supply areas not close to the river). And last of all there has to be commitment from the municipality to make public transport over water a success, since a lot of effort has to be put in and sacrifices in the form of high subsidies that have to be made.