Abstract: A method of building a sea wave power plant of the type in which the power plant (11) must be installed near a steep rock wall (1). The installation site is determined inside the rock formation (F), at a distance from the open rock surface (1). A power plant well which is also serving as a building site (3) is blasted out from the rock formation with a natural rock wall (4) separating the well from the sea. After the plant is completed, the well is filled with water and the partition wall is removed by blasting, opening the well to the sea.

Abstract: Floating platform structure comprising a deck section and a support section supporting the deck section. The floating structure is manufactured in the shape of a trussed girder having an upper chord and a lower chord which are connected with one another by girder members and having a vertical cross section substantially in the shape of a triangle having an apex pointing downwardly, the deck section of the platform structure being provided by the upper chords of the girder. The buoyancy means of the platform structure are found in the upper portions of the girder members and the ballast means in the lower portions of the girder members and optionally in the lower girder chord. The support section comprises groups of at least three girder members each, said members converging from the deck downwardly towards a common point and being fixedly connected with one another in a junction point in or adjacent the convergency point.