A first study regarding internal waves and stratification and the effects on underwater wake. In the far wake, typically 30 hull lengths, it has been proven that, when considering stratification, it has a considerable effect on the evolvement of the wake. When simulating the near field of an underwater object the density is considered to be constant. This is not the case in the oceans where temperature and/or salinity varies and thus creating a stratification. This affects the evolvement of the far wake to suppress the velocity component in the direction of the density gradient and creates big, slow, flat vorticies refered to as "pancake" eddies. Another phenomenon is the internal waves created by the object which, along with the "pancake" eddies, are long lived features of the wake in a stratified medium.