About the International Maritime Organization “2023 Diving Code”

The International Maritime Organization (IMO) Resolution MSC.548 (107), “International Code of Safety for Diving Operations”, also known as the “2023 Diving Code”, adopted during the 107th session of the Maritime Safety Committee on June 5, 2023, to provide a set of guidelines and recommendations, Member States are encouraged to incorporate into their national regulations to enhance the safety of diving operations, has come into force on January 1, 2024, relatively anonymously. Although adherence to it is not compulsory under international law, which means that its implementation by states is not mandatory, this resolution may influence states’ approaches regarding diving operations in their waters. Therefore, it is essential to take into consideration this document of 100 pages to better understand its potential impact on the organization of diving operations.

This Resolution applies to ships of not less than 500 gross tonnage that have a diving system installed on or after January 1, 2024. However, administrations may also consider applying these provisions to smaller vessels and older platforms where practicable. It is also said that coastal states may impose additional or alternative requirements. Note that the dimensions of a vessel with a gross tonnage of 500 tonnes can vary significantly depending on its design and purpose. However, a typical vessel of this size might have an approximate length of 40 to 50 meters, a beam (width) of 8 to 10 meters, and a draft (depth) of 3 to 5 meters. This 2023 Diving Code expands upon the previous Code of Safety for Diving Systems, 1995, and includes guidelines for hyperbaric evacuation systems. Its primary goals are to: • Establish minimum international standards for the design, construction, installation, and survey of diving systems integrated on ships, floating structures, and mobile offshore drilling units (MODUs). • Facilitate safe diving operations from these platforms, ensuring a level of safety comparable to that required by the International Convention for the Safety of Life at Sea (SOLAS). • Enable the international movement and safe operation of diving units. This resolution mandates that every diving unit engaged in operations must hold a Diving Unit Safety Certificate (DUSC), ensuring compliance with safety standards. For this reason, it includes provisions for the suitability of diving platforms, diving equipment design and testing, and the conduct of diving operations, including emergency evacuation procedures. It should be noted that this Diving Code 2023 does not initially apply to the installations and equipment required for the medical care or treatment of patients not related to diving in a pressure vessel for human occupancy (PVHO), nor to diving platforms, including fixed offshore installations, which conduct diving operations but are not covered by SOLAS regulations. However, the text suggests that administrations should consider applying the standards of this Code to such diving platforms and fixed offshore installations to the extent that it is reasonable and practicable to ensure the safety of diving operations. This code may also be applied to a PVHO and associated plant and equipment installed and integrated into a ship for medical treatment. The 2023 Diving Code also allows for alternative arrangements with novel designs to ensure research and development are not hindered. These arrangements must provide an equivalent level of safety deemed satisfactory by the Administration for the intended operation, ensuring the overall safety of the diving unit and operation. Once approved, these alternative arrangements should be documented on the Certificate. To summarize the above texts, the IMO Diving Code 2023, while specifically designed for diving systems installed on ships of not less than 500 gross tonnage from January 1, 2024, can theoretically be extended to other types of vessels and diving equipment. Regarding the reasons for initially limiting this Code to ships over 500 gross tonnage and not smaller units, it must be considered that defining a limit is necessary when establishing rules and that ships of 500 gross tonnage and above typically correspond to supply vessels, multipurpose vessels, and diving support vessels with the infrastructure and resources to support such operations, including those involving saturation diving systems, smaller ships may lack. Also, the Code is designed to align with existing maritime safety regulations, particularly the International Convention for the Safety of Life at Sea (SOLAS). By focusing on large vessels, the Code can better integrate with SOLAS requirements, which already impose rigorous safety standards on ships of this size. Thus, this approach facilitates a more coherent regulatory environment for maritime safety, ensuring that larger vessels are equipped to handle the complexities of diving operations while maintaining compliance with international standards.

However, as mentioned above, while the primary focus is on ships over 500 gross tonnage, the Code is reasonable and practicable. This flexibility acknowledges that some smaller vessels may also engage in diving operations, albeit with the recognition that they may not have the same level of resources or operational complexity as larger ships. It is essential to take into account that the Code is based on the established instruments referenced in the table below to ensures a robust framework.

The survey and certification process for diving systems involves a two-part certification due to the potential for different ownership or operation of the diving system and platform. A "Diving unit" includes both the diving system and the diving platform. Part I of the certification pertains to the diving unit, while Part II pertains to the diving system (a model certificate is available in Appendix 2 of the document). Each diving unit must undergo specific surveys as part of this process. • Initial Survey: Conducted before the diving unit is put into service or before the first issuance of the Certificate, ensuring compliance with integration, safety, and functionality standards. This includes verifying the diving system, equipment, fittings, arrangements, and materials to ensure full compliance with this Code. • Certification Confirmation: Verification if the diving system is already certified under the existing Code. • Installation Survey: Required by DUSC Part II before issuing DUSC Part I. • DUSC Part II Issuance: For non-certified systems, valid until 1 January 2029, specifying unconfirmed provisions. • Renewal Survey: Conducted at intervals not exceeding five years to ensure ongoing compliance. • Annual Survey: Conducted within three months before or after the Certificate's anniversary to ensure continued compliance and functionality. Additional points include the need for inspections after defects, accidents, or significant repairs and the requirement that surveys be conducted by authorized personnel. The certificates are issued by the Administration and are valid for up to five years. They must be in the Administration's official language and include a translation into English, French, or Spanish if necessary. Extensions of up to five months are possible, subject to an annual survey. Every diving system or unit with a Certificate of this Code is subject to control by authorized officers of another Administration to verify the Certificate's validity. The Certificate should be accepted unless there are clear reasons to believe the diving system or unit does not match the Certificate's details. In such cases, the officer may take steps to allow temporary operation without undue risk to divers and personnel. If intervention is necessary, the officer must inform the Administration, Consul, or nearest diplomatic representative of the State where the unit is registered, in writing, of all circumstances. Notwithstanding the above, this Code does not affect the coastal State's rights under international law to impose its own regulations on diving units operating on its seabed and subsoil. The Code is organized into five chapters, covering: • General Provisions: Outlines the overall goals and functional criteria. • Diving Unit Principles: Discusses redundancy and integration of diving systems. • Operational Capabilities and Limitations: Addresses the requirements for safe diving operations. • Diving System Design, Construction, and Survey: Details the standards for diving equipment and systems. • Diving Operations and Safety Management: Focuses on operational safety and emergency preparedness. Complementary information is provided in three appendices. • Appendix 1: Additional Guidance • Appendix 2: Model form of diving unit safety certificate • Appendix 3: Guidance on the Implementation of the Code of Safety for Diving Operations

Chapter 1 - General This chapter emphasizes that each diving unit must possess a Diving Unit Safety Certificate (DUSC) Part I, and each diving system must have a DUSC Part II, as mentioned previously. It explains how these certificates are issued after initial or renewal surveys to ensure compliance with the Code and how they are issued by the Administration or an authorized entity, in line with SOLAS regulation XI-1/1, with the Administration holding full responsibility. It also explains that the DUSC must follow the format in Appendix 2 of the Code and be translated into English, French, or Spanish if it is not originally in one of these languages, and that the systems and equipment mentioned in the Code must meet performance standards equivalent to those of SOLAS unless otherwise specified.

Chapter 2 - Diving unit principles - Redundancy and integration This chapter outlines the requirements and guidelines for ensuring redundancy, safety, and integration of a diving system within a diving platform. The document is structured into the four following sections, each focusing on different aspects of redundancy and safety measures: 1. The section “Redundancy Level and Risks External to the Diving Activity” emphasizes the need for fault tolerance, risk assessment, and systematic reviews to ensure the safety and operational integrity of life-support-critical equipment and systems in the diving unit. 2. The section “Redundancy and Essential Services” aims to guarantee the safety of the diving unit by ensuring it can withstand failures without posing hazards. It highlights design and testing requirements, compliance with standards, and the need for backup systems and systematic risk reviews. 3. The section “Enabling Evacuation and Protection from External Events” evaluates the diving unit's ability to endure accidental events and ensure the safe recovery and evacuation of divers. It includes guidelines for redundancy, emergency services, systematic risk reviews, and documentation. 4. The section “Integration of the Diving System and Diving Platform to Create the Diving Unit” focuses on managing and documenting the integration of the diving system with the diving platform, ensuring they function together as a cohesive unit. It includes guidelines for creating block diagrams, testing systems post- integration, and verifying compliance with specific codes and standards.

Chapter 3 - Operational capabilities and limitations of diving platforms for conducting safe diving operations This chapter outlines the operational capabilities and limitations of a diving platform to ensure safe diving operations. It comprises the seven following sections: 1. The section “Geographic Location and Environmental Conditions” discusses the elements for the diving unit to operate safely under expected environmental conditions, including air and water temperature ranges, wind, sea state, and diving depth. It says the unit must have a defined safe operating envelope for operational and standby conditions. 2. The section “Structural Integrity and Imposed Loads” Sets minimum standards for structural loads and connections, ensuring the chamber complex is supported and protected from pressure, temperature changes, damage, and collisions. Supporting structures must meet recognized standards and be tested accordingly. 3. The section “Placement and Configuration of Diving System” explains that the diving systems are appropriately placed and configured to avoid risks from propulsion, anchoring, and mooring systems. It includes protection from hazardous gases, noise, vibration, impacts, and sea conditions, as well as systems that must comply with electrical safety standards and have safe gas venting and storage measures. 4. The section “Subdivision and Stability” provides elements for the platform and diving system to remain stable and not capsize, providing sufficient time for personnel evacuation. It includes criteria for recovering diving equipment after damage and maintaining essential equipment operability during flooding. 5. The section “Position Keeping” discusses how the diving unit should maintain its position during operations, with systems in place to prevent unsafe situations in case of failure. It emphasizes that Dynamic positioning or mooring systems must comply with specific guidelines. 6. The section “Fire Safety” describes the minimum fire safety standards, including protecting pressure vessels from heat, safeguarding essential equipment, and ensuring adequate fire detection and extinguishing systems. It also requires the use of fire-retardant materials and structural fire protection. 7. The section “Electrical Power” defines minimum electrical power standards, ensuring the diving unit has a reliable power supply for essential services and evacuation. It highlights that an independent power source must be available in case of main power failure, with adequate normal and emergency lighting

Chapter 4 - Diving system design, construction, installation, testing, and survey This chapter outlines the minimum international standards for the design, construction, installation, testing, and survey of diving systems on diving platforms. It is composed of the fifteen following sections: 1. The “Diving System Design” section emphasizes safety, reliability, and minimizing human error. Systems must be designed for specific environmental conditions, using appropriate materials and standards, and include safety, control, and operational requirements. 2. The “Pressure Vessels for Human Occupancy (PVHO)” section ensures the safety of personnel within PVHOs, including surface compression chambers and diving bells. Requirements include safe environments, ergonomic design, and emergency medical facilities. 3. The “Hyperbaric Survival Craft (HBSC)” section provides guidelines for manned evacuation living compartments, ensuring safety during handling operations and emergencies. It includes requirements for toilet facilities, safe access, and emergency provisions. 4. The “Other Pressure Vessels” section focuses on vessels not intended for human occupancy, particularly those containing gases with high oxygen content. It emphasizes appropriate materials and designs and compliance with national or international standards. 5. The “Wet Bells and Dive Baskets” section provides elements to ensure safety during the deployment and recovery of surface- oriented divers, providing protection and necessary onboard facilities. 6. The "Pipes, Valves, Fittings, and Hoses" section defines elements to ensure these components are fit for purpose, minimize noise and vibration, ensure oxygen compatibility, and protect piping systems from damage. 7. The "Breathing Gas Supply, Storage, and Temperature Control" section defines standards for breathing gases, ensuring adequate quantities and quality, and maintaining thermal balance for divers and PVHO occupants. 8. The "Diving Launch and Recovery Systems (LARS)" section provides guidelines for divers' safe deployment and recovery, considering environmental and operational conditions and providing secondary recovery means in case of primary system failure. 9. The "Hyperbaric Survival Craft (HBSC) Deployment Device:" section provides guidelines for the safe transfer of divers from the diving system to the water, ensuring compliance with the Life-Saving Appliance Code. 10. The "Fire Protection" section explains elements for fire safety within the diving system, including the use of fire-retardant materials and effective fire-extinguishing systems. 11. The "Electrical System" section describes the functionality and safety of electrical systems and how to maintain essential services and protect personnel from electrical hazards. 12. The "Control Systems" section provides centralized control for safe operation, continuous monitoring of life-support parameters, and compliance with standards. 13. The "Communication and Location Systems" section describes effective communication between operational control points and, during emergencies, with secondary systems and emergency locating devices. 14. The "Maintenance and Testing" section establishes criteria for maintaining diving systems in safe working conditions, including risk-based planned maintenance and compliance with standards. 15. The "Hyperbaric Survival Craft (HBSC)" section explains the escape capability for divers under pressure, the lifeboat requirements, the possible deviations, and the necessary equipment and consumables.

Chapter 5 - Diving operations and safety management This chapter establishes a minimum international standard for conducting diving operations from a diving unit, in line with the International Safety Management (ISM) Code. It comprises the five sections below. 1. The section “Diving Operations from the Diving Unit” explains the requirements for integrating diving operations into the safety management system, using the diving unit within its design capabilities, ensuring the availability of procedures, plans, and qualified personnel, defining roles, maintaining equipment, communicating findings, identifying hazards, and updating procedures. 2. The “Occupational Health and Safety Management System for Diving Organizations” section outlines procedures for maintaining a certified health and safety management system, aligning procedures with national and international regulations, identifying critical services and equipment, and integrating safety management systems if the diving organization and the responsible company are the same. 3. The “Manning and Training” section explains requirements such as staff diving units with certified medically fit personnel, ensuring qualifications are valid and roles are clearly defined, providing necessary training, and ensuring personnel understand relevant rules. 4. The “Emergency Preparedness” section explains how to identify potential emergencies, establish response procedures, conduct drills and maintain a safety management system, develop evacuation plans and cooperate with search and rescue services, and include standby diving units in contingency planning. 5. The “Voyage Planning” section provides elements to ensure adequate information for safe operations and environmental protection. It also considers hydrographic information, fixed structures, moored vessels, and operational limitations, in addition to complying with the Polar Code for operations in such waters.

Appendix 1 - Additional guidance This document provides detailed complementary guidelines to chapters 3, 4, and 5 regarding the operational capabilities and limitations of diving platforms, diving system design, construction, installation, testing, survey, diving operations, and safety management. It emphasizes the importance of safety, proper equipment maintenance, and adherence to international standards to ensure the well-being of divers and the successful execution of diving operations. It discusses the following topics: Chapter 3 • Guidance on the placement and configuration of the diving system on the diving platform. • Guidance on subdivision and stability. Chapter 4 • Guidance on diving system design. • Guidance on pressure vessels for human occupancy (PVHO). • Guidance on pipes, valves, fittings, and hoses. • Guidance on breathing gas supply, storage, and temperature. • Guidance on diving launch and recovery systems (LARS). • Guidance on fire protection. • Guidance on electrical system. • Guidance on control systems. • Guidance on maintenance and testing. Chapter 5 • Guidance on diving operations from the diving unit. • Guidance on the diving organization's occupational health and safety management system. • Guidance on manning and training. • Guidance on emergency preparedness. • Guidelines for hyperbaric evacuation planning

Appendix 2 - Model form of diving unit safety certificate Diving unit safety certificate - Part 1 This part of the document is the template for certifying a diving unit and its associated diving system under the authority of a government. It includes fields for the name and official number of the diving unit, the authority issuing the certificate, and the date of initial certification. The template also specifies whether the diving system is a saturation diving system or a surface-oriented diving system, along with their respective operating parameters such as maximum operating depth, air and water temperature ranges, maximum wind speed, sea state, and the number of divers. The certificate confirms that the diving system complies with the 2023 Code of Safety for Diving Operations. It verifies that the Part II certificate has been issued by a recognized organization, that the installation meets the 2023 Diving Code requirements, and that essential services and hyperbaric survival craft are in place and tested. The diving unit's International Safety Management (ISM) system must be updated with contingency planning and integrated with the diving organization's occupational health and safety management system. The certificate is valid until a specified date, and it includes the completion date of the survey, the place of issue, and the signature and seal of the authorized official. Diving unit safety certificate - Part 2 This part of the document outlines the details and requirements for the certification of a diving system under the 2023 Diving Code, adopted by resolution MSC.548(107). It specifies that the certificate does not confer acceptance by an Administration nor provide complete certification. The document includes fields for the name and identifying number of the diving system, certifying authority, and whether the system was previously certified under the 1995 Diving Code. It also requires details about the system's first certification date and the validity of the certificate when accompanied by an installation survey. Also, the document distinguishes between saturation diving systems and surface-oriented diving systems, listing their respective operating parameters such as maximum operating depth, air and water temperature ranges, wind speed, sea state, and the number of divers. It certifies that the diving system has been surveyed and tested according to the 2023 Diving Code and meets all relevant provisions. The certificate is valid until a specified date and must be endorsed by an authorized official. Annual surveys and endorsements for certificate extensions are also required, with spaces for signatures, dates, and official seals.

Appendix 3 - Guidance on implementation of the code of safety for diving operations This document outlines the transition from the 1995 Diving Code to the 2023 Diving Code, emphasizing the latter's more comprehensive and goal-based approach. The 2023 Diving Code includes new provisions for integrating diving systems with ships, which were not covered in the 1995 Code. It introduces a two-part certification scheme: Part I for the diving unit (ship with diving system) and Part II for the diving system itself. The text details the issuance, scope, and requirements of these certificates, including the need for periodic surveys and the handling of temporary diving systems. It also addresses the certification of existing uncertified diving systems and provides guidance on alternative solutions for mandatory requirements, such as means of escape and life-saving appliances. The alignment of safety management systems between the ship and diving operations is also emphasized.

To conclude The International Maritime Organization (IMO) Resolution MSC.548 (107) "International Code of Safety for Diving Operations" strengthens the requirements of IMO Resolution A.831(19), 1995 "Code of Safety for Diving Systems". The technical level required by the code is comparable to that of most known diving organizations. Therefore, it can be considered a good framework for states wishing to develop their national regulations, provided that such documents are written by specialists competent for this purpose to avoid editing inconsistent rules, as has been unfortunately seen in the past for the regulations of some countries. Of course, although this document provides a substantial amount of information, it is important to remember that this 100-page code only offers an overview of how diving systems should be organized and operated. Therefore, it cannot cover all aspects and details of diving operations, and additional guidelines may be required to compile national legislation. In this regard, please note that our database contains more scientific and technical documents than most professional organizations, which can be used as references and are free of charge. Additionally, the "Diving and ROV Specialists" manuals and CCO Ltd studies summarize the information from these references into ready-to-use documents, citing the scientific and technical sources used, which can be downloaded from our database or the publisher's website.  It is too early to determine whether states will adopt this document for use in compiling their rules, as many classification societies acting on behalf of states have already developed their own guidelines for the certification of diving systems and diving support vessels. It should be noted that diving companies currently implementing the guidelines of organizations such as NORSOK will not be affected in their operations by the guidelines of the resolution. The only inconvenience will be the addition of a new set of certificates to the many that already exist. The button below provides access to the IMO diving code 2023