you can just set collissionFidelity property of the model to preciseDecomposition and that should take care of it New Studio Feature - CollisionFidelity.PreciseConvexDecomposition (Enabled Globally), you can also cut the boat into different peaces so that instead of concave most of the individual pieces are convex if you are making it in blender (you would separate a cubic room into floor, each wall separately and roof) and import it into roblox afterwards, i’d suggest using this plugin Show Decomposition Geometry Plugin to be able to iterate rapidly with your shapes and see what works out the best