Software for real-time estimation of flooding risk onboard passenger ships (or ships in general) should be capable of identifying a potential hazard and evaluating a risk level associated with the detected danger. The present work presents a framework for real-time risk assessment in case of potential ship-to-ship collisions. As real-time risk assessment pertains to both phases before and after an accident, the present work focuses on the risk of flooding before an accident occurs. More precisely, the paper describes the step necessary to develop a database-based software for real-time risk assessment during navigation, focusing on the detection and likelihood of possible ship-to-ship collisions potentially dangerous for the ship. As such, the tool should be capable to identify a hazard, evaluating the risk level associated with the hazard and advise the crew of potential risks. The software should work in symbiosis with onboard instrumentation, receiving data from, for example, Radar, GPS and AIS in real-time. Given these inputs, the software should calculate the route of potential striking ships, estimating the possible future collision. Afterwards, in case of possible collisions, the software interrogates a damage surrogate model derived from a database of direct crash simulations, providing in real time a set of potential breaches. Such breaches are then associated with a time to capsize, derived from a survivability surrogate model derived from a set of time-domain flooding simulations. Then it is possible to evaluate risk as the Potential Loss of Life (PLL) in real time. Such an approach is fully based on direct first-principles calculations and compliant with the multilevel framework developed in project FLARE for flooding risk.