This chapter distinguishes the technological and infrastructural network vulnerability models into two types. The first are the complex-network-based vulnerability models, which do not consider the flow transportation and redistribution or measure the system performance drop only according to topological change, where the performance is usually measured by the size of the largest connected sub-grid, the connectivity level or loss, the fraction of affected customers. The second type are real flow models, which use equations and engineering constraints to describe the performance drop of networks undergoing a disruptive event. For studying vulnerability and resilience of ports and maritime networks, it seems relevant to use the first type of vulnerability models. A maritime network in its simplest form is just a set of nodes or vertices joined together in pairs by lines or edges. The chapter also investigates network representation of the maritime network from topological and geometrical perspectives in the hope of finding properties and behaviours that transcend the abstraction.