Koos is the largest of several small islands in the Bay of Greifswald, Mecklenburg-Vorpommern, Germany. It has an area of 772 hectares and a maximum elevation of just above three meters. The island is a largely uninhabited natural reserve with restricted access. It is separated from the mainland by Kooser Bucht and Kooser See, two bays connected by …Koos is the largest of several small islands in the Bay of Greifswald, Mecklenburg-Vorpommern, Germany. It has an area of 772 hectares and a maximum elevation of just above three meters. The island is a largely uninhabited natural reserve with restricted access. It is separated from the mainland by Kooser Bucht and Kooser See, two bays connected by a tiny strait, Beek.