This instruction provides guidelines for the occupational safety and health standards for commercial diving operations, 29 CFR Part 1910, Subpart T. This instruction provides guidance to Occupational Safety and Health Administration (OSHA) National, Regional, and Area Offices; industry employer and employee groups; State programs; and federal agencies concerning OSHA's policy and procedures for implementing intervention and inspection programs to reduce injuries, illnesses and fatalities, and to eliminate workplace hazards found in commercial diving operations. This instruction provides tools to support intervention and inspection programs in the commercial diving industry. This instruction: Supports the reduction of occupational exposure to hazards through direct intervention, and promotes a safety and health culture through compliance assistance, cooperative programs, and strong leadership. Maximizes OSHA's effectiveness and efficiency by strengthening its capabilities and infrastructure. This instruction has been revised and updated to include significant changes as follows: Provides OSHA compliance officers, consultants, and other interested government and industry parties with information to support interventions involving commercial diving operations and to minimize employee exposure to hazards. Provides additional answers to commonly asked questions related to commercial diving operations in Appendix A. This appendix consolidates all previously issued interpretations of OSHA's commercial diving operations standards. Provides additional clarification of the requirements and duties of diver tenders (Appendix E). Updates the instruction to ensure that current editions of other OSHA instructions, as well as industry standards and manuals, are referenced (e.g., CPL 02-00-150, Field Operations Manual (FOM), April 22, 2011, and Association of Diving Contractors International, Consensus Standard for Commercial Diving and Underwater Operations (6th Edition)). Updates Appendix D of this instruction related to no-decompression air dives based on Revision 6 to the U.S. Navy Diving Manual. Adds electronic links to enhance web-based usability.