The production of mineral oil in the sea bed and its storage in situ has become an extremely important factor for the world's economy. The development of equipment necessary for such projects, in particular drilling platforms and large storage tanks, has become an important task for research scientists in all industrial countries. Such tasks include environmental investigations in the various regions and research into the most important of the ocean's phenomena, such as the wind, the motion of the sea, currents, the drift of ice etc. and the provision of the necessary means of producing a quantitative record of such phenomena. First and foremost it is necessary to ascertain the forces to which typical marine structures are subjected by the wind and the motion of the sea, whereby the structures mainly affected are fixed and floating platforms and cylindrical storage tanks. Various construction methods are dis cussed, with illustrations of structures already in use. Stress and oscillation caused by static and dynamic forces, when the structures are exposed to the wind and the motion of the sea, are demonstrated. Various types of foundation available for platforms and tanks designed to stand on the sea bed are also discussed, whereby the bearing capacity of the latter is an extremely important factor. Details of suitable materials are given and reference is made to the problems which these materials entail when used for marine purposes.