A buoyancy system is disclosed for use in controlling the descent and ascent of an object, such as a pipe line being laid offshore. The system includes a plurality of inflatable, collapsible, submersible buoys which may be remotely controlled by air or other inflating mediums. As each of the buoys, and...http://www.google.de/patents/US4121529?utm_source=gb-gplus-sharePatent US4121529 - Buoyancy systems
