The short version
- 46 CFR 197.314(a)(1) requires a medical kit approved by a physician at every dive location, and gives no contents list.
- There is no mandatory diving medical examination anywhere in 46 CFR part 197 subpart B. The full section list was read to confirm it.
- A decompression chamber is required by 197.314(c) if the dive uses mixed gas, goes deeper than 130 fsw, or runs outside no-decompression limits. Any one is enough.
- 197.454 repeats the first aid equipment heading in the periodic inspection group, so the physician approval is recurring, not one time.
- ADCI and IMCA periodic medicals are consensus standards or contract terms, not the CFR.
The rule says a physician approves the kit, and stops there
United States commercial diving from a vessel is governed by 46 CFR part 197 subpart B, and the operative medical sentence is four words long. Section 197.314(a)(1) requires each dive location to carry a medical kit approved by a physician.[1]
The regulation does not name the physician, set a specialty, define a contents list, or say how the approval is recorded. It creates a duty and leaves the whole method to the operator.
That is the same drafting pattern as 46 CFR 28.210 on fishing vessels, which requires a medicine chest and never says what goes in it. Two different subchapters, written decades apart, arriving at the same gap.
The rest of 197.314(a) is specific where the kit is vague. A dive location must also carry a copy of an American Red Cross Standard First Aid handbook, a bag type manual resuscitator with a transparent mask and tubing, and a means of removing an injured diver from the water.[1]
What the search results hand a US dive contractor instead
Search the medical requirements for commercial diving and the first page returns the raw statute and nothing else: the eCFR text of part 197, a Cornell mirror of the same text, a govinfo PDF of the 2010 print edition, a statute aggregator, and a Washington State labour and industries chapter.
Not one page translates the text for the person who has to comply with it. There is no operator guide, no contents discussion, no explanation of which sections attach to which dive.
That absence is the same shape we found on mobile offshore drilling units and on small passenger vessels : a United States rule exists, and nothing on page one explains it.
The second defect is louder. Ask the same question in general terms and the answer arrives from the wrong jurisdiction and the wrong body entirely. The Association of Diving Contractors International consensus standards and the International Marine Contractors Association guidance both require a periodic diving medical examination. Those are industry consensus documents, not United States federal law, and a contractor who assumes the CFR carries the same requirement has read a private standard as a regulation.
There is no mandatory diving medical in subpart B
This is the finding most likely to surprise a contractor coming from the North Sea or from an ADCI card scheme, so it is worth stating precisely and showing the working.
The complete section list of 46 CFR part 197 subpart B runs from 197.200 to 197.488 across six subject groups: General, Equipment, Operations, Specific Diving Mode Procedures, Periodic Tests and Inspections, and Records.[2] No section in that list requires a diver to hold a medical certificate, undergo a periodic examination, or be declared fit by a physician.
What subpart B does instead is push the assessment onto the dive itself. Section 197.410(a) requires the diving supervisor to ensure that each diver is instructed to report any physical problems or physiological effects including aches, pains, current illnesses, or symptoms of decompression sickness before each dive.[3] After the dive, the same section requires the diver’s physical condition to be checked by visual observation and by questioning the diver about their physical well being.[3]
The distinction that matters commercially
Federal law requires a self report and an observation, repeated every dive. Industry consensus standards require a periodic examination. A contract, a client audit or a state programme can make the examination binding on you. The CFR does not.
A fleet operating under a client contract that incorporates ADCI or IMCA by reference is bound by that contract, not by part 197. Knowing which document is imposing the requirement changes who you argue with when it is disputed. Our maritime medical consulting line exists for exactly this kind of separation.
The pattern repeats across this site. US commercial fishing is answered with UK ENG1 certificates, offshore supply vessels with EU and Dutch material, and towing vessels with the wrong subchapter.
Two tiers of equipment, set by depth and gas
Section 197.314 is written in two layers. Paragraph (a) applies to every dive location. Paragraph (c) adds a second layer when the work crosses a threshold.
| Requirement | Every dive location, 197.314(a) | Mixed gas, deeper than 130 fsw, or outside no-decompression limits, 197.314(c) |
|---|---|---|
| Medical kit | Approved by a physician[1] | Also portable into the chamber and usable under pressure[1] |
| First aid reference | American Red Cross Standard First Aid handbook[1] | Plus decompression and treatment tables[1] |
| Airway and ventilation | Bag type manual resuscitator, transparent mask, tubing[1] | Same, plus sufficient breathing gas to treat decompression sickness[1] |
| Casualty handling | A means of removing an injured diver from the water[1] | Plus a means of assisting an injured diver into the chamber[1] |
| Chamber | Not required[1] | A decompression chamber is required[1] |
The threshold in paragraph (c) is not a single number. It is met by any of three conditions: the dive uses mixed gas, the dive goes deeper than 130 feet of sea water, or the dive is conducted outside the no-decompression limits. A 90 foot air dive that runs long enough to require in-water decompression crosses the line as surely as a 200 foot dive does.
Chamber construction and marking sit separately at 197.332, which governs pressure vessels for human occupancy.[4] Section 197.330 covers closed bells and 197.334 covers open diving bells.[2]
The kit has a maintenance clock most programmes miss
Section 197.314 puts the kit aboard. Section 197.454, in the Periodic Tests and Inspections group, keeps it usable.[2] The two sections carry the same heading, First aid and treatment equipment, which is why a compliance matrix built by searching on section 197.314 alone comes up one row short.
This is the practical consequence: the physician approval that satisfies 197.314(a)(1) is not a one time event. A kit approved in March and depleted in July is not an approved kit in July. Running the inspection interval, restocking against the approved list and re-documenting the approval is a recurring programme, which is what our ship medical chest management service delivers on a schedule. The mechanics are the same ones set out in how to stock a ship medicine chest and audited the way an inspector checks a programme .
Check the controlled substance line separately
If the physician approved kit contains any controlled substance, the diving rule is no longer the only rule in play. Possession aboard a vessel engages 21 CFR 1301.25, which requires either a DEA registered medical officer employed by the owner or operator, or the master requisition route. Read the 21 CFR 1301.25 walkthrough and the two route comparison before stocking. Disposal of what expires is covered in the vessel disposal walkthrough and the record set in recordkeeping aboard a vessel .
Who carries the duty, and who signs
Subpart B splits accountability between two named roles, and a dive contractor who conflates them has no defensible chain when a casualty is investigated.
| Role | Named at | Medical relevance |
|---|---|---|
| Person in charge | 197.208, designated in writing; duties at 197.402[2] | Vessel side authority. Owns the interface between the dive and the vessel, including casualty notification |
| Diving supervisor | 197.210, designated for each operation; duties at 197.404[2] | Runs the pre-dive brief, the illness self report and the post-dive check under 197.410[3] |
| Physician | 197.314(a)(1), no further definition[1] | Approves the kit. The regulation says nothing else about them, which is the whole gap |
Note what the table shows about the physician row. The two operational roles are designated, defined and given a duty list. The physician is invoked once and never described. Nothing in subpart B requires the approving physician to be reachable during the dive, to hold hyperbaric training, or to review the kit again.
An operator who wants that physician to be more than a signature has to build the arrangement themselves. The same problem appears in the owner and DPA responsibility split and in the six decisions that come first when a programme is designed.
Which dives part 197 subpart B actually reaches
Applicability sits at 197.202, and it is narrower than the phrase commercial diving suggests.[2] Subpart B reaches commercial diving operations from vessels and facilities under Coast Guard jurisdiction. Scientific diving and diving conducted solely for instruction or recreation sit outside it, and OSHA’s own commercial diving standard at 29 CFR part 1910 subpart T covers a different and partly overlapping population.[5]
The consequence for a mixed fleet is real. A workboat supporting a pipeline repair and a research vessel running a survey dive can be side by side and answer to different rule sets. Our uninspected vessel analysis and the Subchapter L review deal with the same class by class fragmentation on the kit side, and the kit comparison by class lays the whole picture out in one table.
The casualty chain has a clock and a retention rule
Three sections in the Records group turn a diving injury into a reporting obligation, and they are separate from the general marine casualty rules an operator already knows.
| Section | Trigger | Duty |
|---|---|---|
| 197.484 | Diving casualty[2] | Notice of casualty to the Coast Guard |
| 197.486 | Following the notice[2] | Written report of casualty |
| 197.488 | After a casualty[2] | Retention of records |
Logbook obligations sit alongside them at 197.480 and 197.482.[2] A dive log that records the self report under 197.410(a) and the post-dive check is the document that shows the medical procedure was followed, which matters far more after an incident than before one.
The general marine casualty question, what counts as treatment beyond first aid, is answered in our analysis of the reporting threshold. Death on board covers the worst case, and crew medical records covers who may see the file afterwards.
What to fix this quarter
- Name the approving physician in writing. Section 197.314(a)(1) requires physician approval and no record format. Absent a document, you cannot show the approval happened.[1]
- Attach the approved contents list to the approval. The regulation gives no list, so yours is the only evidence of what was approved.
- Split the matrix by 197.314(a) and 197.314(c). Confirm which of your dive profiles cross mixed gas, 130 fsw, or the no-decompression limits, because that decides the chamber.[1]
- Add 197.454 to the inspection schedule. Same heading, different section, easy to miss.[2]
- Check the kit against 21 CFR 1301.25 if it holds any controlled substance.
- Record the 197.410 self report and post-dive check in the dive log, not just in practice.[3]
- Separate contract obligations from federal ones. Write down which of your medical requirements come from ADCI, IMCA or a client, and which come from the CFR.
Discovery Health MD is led by Ann Jarris MD, MBA, FACEP, a board certified emergency physician. Physician approval of a dive medical kit, and the recurring re-approval that keeps it valid, is work we do. If the fleet also runs long voyages far from definitive care or changes flag state , the same physician arrangement covers both. Speak to the team.
Common questions
Does 46 CFR 197 require a diving medical examination?
No. The full section list of 46 CFR part 197 subpart B, from 197.200 to 197.488, contains no requirement for a periodic diving medical examination or a fitness certificate[2]. Section 197.410(a) instead requires each diver to be instructed to report physical problems, aches, pains, current illnesses or symptoms of decompression sickness before each dive, and requires a post-dive check by visual observation and questioning[3]. Periodic examinations come from ADCI and IMCA consensus standards or from a client contract, not from the CFR. Our consulting service separates the two.
What must be in a commercial diving medical kit?
Federal law does not say. 46 CFR 197.314(a)(1) requires a medical kit approved by a physician and gives no contents list[1]. The same paragraph does specify the rest: an American Red Cross Standard First Aid handbook, a bag type manual resuscitator with a transparent mask and tubing, and a means of removing an injured diver from the water[1]. Because the contents are undefined, the approved list you write is the only evidence of what was approved. That is what our MedChest service produces.
When is a decompression chamber required on a US dive job?
When any one of three conditions is met, under 46 CFR 197.314(c): the dive uses mixed gas, the dive goes deeper than 130 feet of sea water, or the dive is conducted outside the no-decompression limits[1]. Meeting one is enough. The same paragraph then requires decompression and treatment tables, sufficient breathing gas to treat decompression sickness, a kit that is portable into the chamber and usable under pressure, and a means of assisting an injured diver into it[1]. Chamber construction sits at 197.332[4].
Who is the physician in 46 CFR 197.314?
The regulation never says. It requires a medical kit approved by a physician and adds no definition, no specialty, no hyperbaric training requirement and no obligation for that physician to remain reachable[1]. That silence is why the approval is worth building around rather than treating as a formality. Discovery Health MD is led by Ann Jarris MD, MBA, FACEP, a board certified emergency physician, and our consulting line covers exactly this kind of undefined duty.
Does OSHA or the Coast Guard regulate commercial diving?
Both, over different populations. 46 CFR 197.202 sets the applicability of the Coast Guard rule to commercial diving from vessels and facilities under its jurisdiction[2], while OSHA runs a separate commercial diving standard at 29 CFR part 1910 subpart T[5]. Scientific diving and diving solely for instruction or recreation sit outside subpart B[2]. A mixed fleet can have two vessels alongside each other answering to different rule sets, which is a scoping question worth settling in writing.
How often does the diving medical kit have to be checked?
46 CFR 197.454 places first aid and treatment equipment in the Periodic Tests and Inspections group of subpart B[2]. It carries the same heading as 197.314, which is why compliance matrices built by searching the equipment section alone miss it. The practical point is that physician approval is not a one time event: a kit approved in March and depleted by July is no longer the approved kit. Read how a vessel medical compliance audit checks this.
What has to be reported after a diving casualty?
Three separate sections. 46 CFR 197.484 requires notice of casualty, 197.486 requires a written report of casualty, and 197.488 requires retention of records after a casualty[2]. Logbook duties sit alongside at 197.480 and 197.482[2]. These are additional to the general marine casualty rules, and the dive log entry recording the 197.410 self report and post-dive check is what shows the medical procedure was actually followed[3].
