Introduction -- Flow scales in cross flow turbines -- Numerical study of 2D vertical axis wind and tidal turbines with a degree-adaptive hybridizable discontinuous Galerkin method -- A MLS-based high-order-preserving sliding mesh technique with no intersections -- Vertical-axis wind turbine start-up modelled with a high-order numerical solver -- Large-Eddy Simulation of a Vertical Axis Tidal Turbine using an Immersed Boundary Method -- Computational Study of the Interaction between Hydrodynamics and Rigid Body Dynamics of a Darrieus Type H Turbine -- The physics of starting process for vertical axis wind turbines -- Hybrid mesh deformation tool for offshore wind turbines aeroelasticity prediction -- Numerical Simulation of Wave Loading on Static Offshore Structures -- MLS-based selective limiting for Shallow Waters Equations --  A Comparison of Panel Method and RANS Calculations for a Horizontal Axis Marine Current Turbine.