Abstract: A system and methods for diverless replacement of a functional component installed on a service unit on a sea bottom-based installation is provided. The component is fitted releasably into the service unit as an insert with an externally extending maneuverable part. The replacement is carried out by a tool mounted on a remotely operated vehicle (ROV). The invention utilizes ROV supported weight compensation means for compensating the weight of the component in order to maintain the ROV in a substantially neutral buoyancy state during operations. The weight compensating means comprises a separate adapter element having the same weight as the component to be replaced. The adapter element or adapter are equipped to be releasably supported by the ROV tool. The adapter has an upper end and a lower end and a central axis extending therethrough, and a centrally extending throughgoing opening having transverse dimensions larger than the largest transverse dimension of the component.

Abstract: A coupling and switch system for subsea electrical power distribution employs fluid-filled contact housings. The coupling and switch system includes two mutually spaced contact housings mounted along a common centerline. A space between the contact housing has therein a coupling housing or middle piece having contact elements. The middle piece when or after mounting between the contact housings is anchored in a fluid-tight manner thereto by axial movement of one or both contact housings. The contact elements of the middle piece can be moved into respective contact housings with the middle piece in the mounted position.