Abstract: A structure (200) for subsea installation has buoyancy distributed substantially along its length in order to float said structure in horizontal orientation to a point of installation. When said structure is upended, said distributed buoyancy maintains said structure in a substantially vertical orientation and operational state, without the need for further, non-distributed buoyancy (for example, without substantial tension being provided by a top buoy or surface vessel (100)). The structure may comprise a flexible or rigid riser conduit for hydrocarbons. Buoyancy modules may be fixed with spaces between them, for example to achieve a structure similar to a SLOR, or COR, but without a top buoy. The buoyancy modules may alternatively be free to slide longitudinally along the structure, so as to impart their buoyancy force through one another to the top of the structure.