The intensification of global trade and travel has resulted in marine non-indigenous species (NIS) being introduced to areas outside their native ranges at increasing rates. Understanding the dynamics of marine vessel networks can boost our ability to prevent incursions (via optimised surveillance) or respond to them (predicting spread). This study presents an adaptable model quantifying the invasion risk of nodes in a domestic maritime transport network based on the potential propagule pressure (PPP) of NIS. We used two complementary proxies for PPP, one to quantify NIS movement on ship hulls based on total wetted surface area, and a second based on movement within ballast water. Focusing on New Zealand’s seascape, we used datasets containing commercial and recreational vessel movements standardised to a one-year period and conducted a network analysis to quantify the relative spread of NIS. We found several strong movement corridors between coastal harbours, as well as sites acting as invasion hubs. Importantly, our analyses identified sites that have a high relative risk to incursions but are currently not prioritised for biosecurity management. This framework is directly applicable and relevant to the Australian maritime system and can be used to inform prioritisation for surveillance, pathway management and incursion response.