In the last decades an increasing interest in offshore wind energy has been observed. The main reason for ’going offshore’ may be the higher and more constant wind resource at sea than on land, leading to a higher energy production per wind turbine. Nevertheless to properly install wind farms is necessary to study the offshore conditions of each possible location. The limited knowledge about offshore conditions, compared to onshore conditions, motivates the use of numerical methodologies to study the offshore boundary layer. During part of my research at von Karman Institute, I performed some simulations of a free and forced convective boundary layer using initial and boundary conditions based on measurements performed by an offshore platform.