A resting device (1) of at least one portion of a linear structure (2) is for crossing an uneven underwater topography. The resting device (1) is suitable for supporting at least one portion of the linear structure (2) that defines a longitudinal direction (X-X) coincident with or parallel to the longitudinal development direction of the linear structure (2). The resting device (1) includes at least one buoyant element (3) and at least one tether (4), suitable for constraining the resting device (1) to a bed (5). The at least one buoyant element (3) is suitable for providing a sufficient buoyancy to keep the at least one tether (4) under tension. A deck (6) has a shape and material that allows distributed resting of at least one portion of the linear structure (2) on the resting device (1).