Abstract: A device is described for a foundation to be placed in a sea bed, comprising a housing-formed, downwardly open, coat-forming construction set up for placing in the sea bed, said construction comprises a top part, and the top part comprises an extended hollow body (140) that stretches a distance into the inside of the construction. The invention is characterised in that the length of the inner pipe is shorter or longer than the length of the coat. When the inner pipe is shorter, its length is of the order of 10-90% of the length of the skirt 10, preferably 25 to 60%, and most preferred 50%. When the inner pipe is longer, its length is more than 100% and up to 300% of the length of the outer coat (10), preferably 150 to 200% and most preferred 300%. A method and different applications are also described.