{"data":{"id":"us/46-cfr-197.322","jurisdiction":"us","citation":"46 CFR 197.322","heading":"Surface-supplied helmets and masks.","body":"(a) Each surface-supplied helmet or mask must have—\n(1) A nonreturn valve at the attachment point between helmet or mask and umbilical that closes readily and positively;\n(2) An exhaust valve; and\n(3) A two-way voice communication system between the diver and the dive location or bell.\n(b) Each surface-supplied air helmet or mask must—\n(1) Ventilate at least 4.5 ACFM at any depth at which it is operated; or\n(2) Be able to maintain the diver's inspired carbon dioxide partial pressure below 0.02 ATA when the diver is producing carbon dioxide at the rate of 1.6 standard liters per minute.","path":["Title 46—Shipping","CHAPTER I—COAST GUARD, DEPARTMENT OF HOMELAND SECURITY","SUBCHAPTER V—MARINE OCCUPATIONAL SAFETY AND HEALTH STANDARDS","PART 197—GENERAL PROVISIONS","Subpart B—Commercial Diving Operations"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-46.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:26:22Z","sha256":"4077e4fd3a544ef3d38fa077351cdd71d83f853d9d503f19560f411f4e709dc8","source_id":"us-cfr","stale":true,"prev":"us/46-cfr-197.320","next":"us/46-cfr-197.324"},"notice":"GroundRules: Original legal text. Not legal advice."}