Accurate simulation of fluid-structure interactions (FSI) remains a difficult task in com- putational mechanics, especially when dealing with complicated geometries and dynamic coupling between fluid and solid domains. This paper introduces novel benchmarks in the field of FSI that take advantage of isogeometric analysis (IGA) and the adaptibility of the preCICE coupling library. We offer a framework that combines the IGA-based solid mechanics library G+Smo, the computational fluid dynamics capabilities of open- FOAM, and the julia-based waterLily.jl fluid solver, aimed at advancing hydrodynamic simulations. Central to our approach is the utilization of unstructured splines within the library G+Smo, which elevates the IGA benefits of higher continuity and reduced discretiza- tion errors towards multi-patch geometries, particularly crucial for complex FSI scenarios. These unstructured splines such as AS-G1, Approx. C1, D-Patch, and Almost-C1, allow for continuous basis functions across patch interface, which brings the advantages such as being parameter-free and not requiring specialized solvers, over traditional methods like trimming or variational coupling [1]. This paper presents several benchmarks, ranging from the replication of established pre- CICE cases for direct comparison with other solid mechanics libraries, to the introduction of novel scenarios not previously studied using the preCICE framework. These bench- marks highlight the potential of unstructured splines in G+Smo, particularly in terms of enhancing adaptability and accuracy in complex FSI simulations. REFERENCES [1] H.M. Verhelst, P. Weinmu ̈ller, A. Mantzaflaris, T. Takacs and D. Toshniwal, A com- parison of smooth basis constructions for isogeometric analysis. Comput. Methods Appl. Mech. Engrg., Vol. 419, 2024.