IMCA Newsroom

Press Release 28/05

IMCA'S GUIDANCE FOR SAFE SURFACE SUPPLIED MIXED GAS DIVING OPERATIONS

Surface supplied diving using a mixture of helium and oxygen as the breathing gas can be used to increase the range or duration of surface diving operations without the use of saturation techniques. However, in general this technique is not an effective alternative to saturation diving.

In particular, the dive plan needs to consider all of the relevant safety implications of using this technique instead of a closed bell. The restricted bottom time in the deeper range results in it only being suitable for limited types of work, such as short duration inspection dives or simple tasks, such as disconnecting a wire.

IMCA - the International Marine Contractors Association - has published a revised version of 'Surface Supplied Mixed Gas Diving Operations' (IMCA D 030), which sets out the limitations of the technique and areas to be covered in dive plans.

This guidance document identifies what is generally regarded in the diving industry as good practice to achieve safe working during surface supplied mixed gas diving operations, with the principal areas covered relating to safety considerations, personnel and equipment requirements.

"The original version of this guidance was prepared by our Asia-Pacific Section and issued in 2003," explains IMCA's Technical Director, Jane Bugler. "This has been reviewed by a workgroup comprising representatives of our Americas Deepwater, Asia-Pacific, Europe & Africa and Middle East & India Sections re-evaluating use of the technique around the world and the hazards and ways in which they can be avoided. The result is an updated document, which gives further information on the operational limits of the technique and issues to be considered during risk assessment. A dedicated DESIGN (Diving Equipment Systems Inspection Guidance Note) is currently being finalised to expand our guidance in this area.

"National regulations may exist in some parts of the world that limit or exclude the use of techniques outlined in the guidance document - for example by restricting depth. In such cases these national regulations must always take precedence over this guidance publication."

The guidance document has sections devoted to safety considerations (operational limits; risk assessment; equipment failure; recovery of an injured diver; and operational method); personnel (divers; supervisors; and manning levels); equipment (diving equipment; decompression facility) as well as sections on the selection of tables; and additional reference sources.

Notes to Editors (common)

• IMCA is an international association with over 450 members in more than 50 countries, representing offshore, marine and underwater engineering companies. IMCA has four technical divisions, covering marine/specialist vessel operations, offshore diving, hydrographic survey and remote systems and ROVs, plus geographic sections for the Americas Deepwater, Asia-Pacific, Europe & Africa and Middle East & India regions, as well as a core focus on safety, the environment, competence and training. IMCA seeks to promote its members' common interests, to resolve industry-wide issues and to provide an authoritative voice for its members.
• IMCA publishes some 200 guidance notes and technical reports. These have been developed over the years and are widely distributed. They are a definition of what IMCA stands for, including widely recognised diving and ROV codes of practice, DP documentation, marine good practice guidance, the Common Marine Inspection Document, safety recommendation, outline training syllabi and the IMCA competence scheme guidance. In addition to the range of printed guidance documents, IMCA also produces safety promotional materials, circulates information notes and safety flashes.
• Judith Patten is here to help you if you want any additional information on IMCA; would like to discuss a feature article; want to organise interviews with key members of the IMCA team, etc.