FIELD: environment control. SUBSTANCE: device includes guard consisting of rigidly interconnected parallel ferrules which are used as compressed air accumulators. Ferrules have blind taper joints at both ends provided with retainers forming interchangeable sections which are connected by means of flexible members for flow of air from one section to another. Sections are brought in communication with compressed air supply device under level of water; each compressed air supply device consists of two concentric tubes with seals between them; in lower portion they have port adjustable in height. Tubes are mounted for turning about vertical axis, as well as for vertical motion and motion along guard. Device provides for control of air flow, depth and direction of its supply, thus excluding diving of foreign matter under guard. EFFECT: enhanced reliability. 2 cl, 9 dwg
