Abstract: A marine structure includes a base which is to be founded upon the sea bed. An elastic pre-stressed column is rigidly fixed to and extends upwardly from the base. A buoyant, rigid structure is fixed to the upper end of the upstanding elastic column. The buoyant, rigid structure includes a submerged part and a part projecting up above the sea level to support a deck superstructure. The pre-stressed elastic column is designed to deflect in a curved manner when the buoyant, rigid structure is subjected to environmental forces. In particular, the first nautral period of the installed structure is longer than the significant exciting wave periods. Accordingly, the main structure will oscillate about its vertical equilibrium when subjected to waves and wind thereby behaving as an articulated column.