The continuous development of the world creates the need for submarine transport and communication. Consequently, seafloor instabilities may create complications in the everyday life of humans. A sustainable design for the lifespan of urban infrastructure is vital for the maintenance of their operation. Statens Vegvesen aims at the completion of the E39 project without having any ferry connections. In the context of E39, a side-anchored floating bridge will be constructed in Bjørnafjorden, and the mooring system will be anchored on the seabed.In the first part, the definition of the problem is given together with the description of the geological situation of Bjørnafjorden’s seafloor. Subsequently, a literature review is provided on landslides. Additionally, a brief description of the mathematical background of DAN3D is included.The stability of the seafloor is a crucial element of the study, and an extensive back-calculation for the determination of the governing geotechnical and rheological parameters is detailed. All the analyses were conducted with the software DAN3D. This study approaches the topic from different aspects. Several empirical approaches are adopted in order to estimate the run-out distance of a given landslide. In the numerical analysis, two rheological models are chosen for the back-calculation of the landslide. Both plastic and frictional rheologies simulate the landslide in a realistic way.Finally, a comparison with NGI’s conclusions is conducted to confirm the correctness of the present study and give a clear overview of the geotechnical conditions in Bjørnafjorden’s seabed. The study concludes with recommendations and suggestions on future work based on the simulation results.