The short version
- Subchapter M contains exactly one medical equipment section, 46 CFR 140.435, and it is two sentences long.
- It is a capability standard, not a contents list. Three outcomes are named and the item list is left to the operator.
- Route decides the tier. Every towing vessel needs an industrial first aid cabinet or kit. Oceans, coastwise and Great Lakes routes add blood pressure, splinting and large wound dressing.
- Subchapter M requires no medicine chest, no medical guide, no designated medical person and no controlled substances.
- 46 CFR 140.900 hands every injury reporting question to 46 CFR part 4, so the towing rules add nothing to the threshold.
The entire medical rule is two sentences
Subchapter M is not small. Parts 136 through 144 cover certification, safety management systems, machinery, electrical systems, construction, lifesaving and firefighting for every towing vessel subject to it. Operators reasonably assume that somewhere in that volume there is a medical annex. There is not. The medical equipment content is a single section in part 140 subpart D, Crew Safety, and it reads in full:
46 CFR 140.435, First aid equipment
“Each towing vessel must be equipped with an industrial type first aid cabinet or kit, appropriate to the size of the crew and operating conditions. Each towing vessel operating on oceans, coastwise, or Great Lakes routes must have a means to take blood pressure readings, splint broken bones, and apply large bandages for serious wounds.”[1]
Two sentences, two obligations, and the second one is triggered by route rather than by size. A harbour assist boat working inside a single port carries the first obligation only. The same company’s linehaul unit running the coast carries both, and nothing in the rule scales with crew number, horsepower or tonnage.
| Tier | Applies to | What the rule demands |
|---|---|---|
| Baseline | Every towing vessel subject to Subchapter M | An industrial type first aid cabinet or kit, appropriate to the size of the crew and operating conditions[1] |
| Route triggered | Oceans, coastwise or Great Lakes routes | A means to take blood pressure readings, a means to splint broken bones, a means to apply large bandages for serious wounds[1] |
Notice what the second tier is written in: verbs. Not a list of splints by size, not a specified cuff, not a quantity of dressings. Three capabilities, and the means of achieving them is yours to choose.
A capability standard, not a contents list
This is the structural point most operators miss, and it changes how the requirement is evidenced. Compare the three regimes an American operator is most likely to encounter. Only one of them tells you what to buy.
| Regime | How it is written | Who carries the burden of proof |
|---|---|---|
| 46 CFR 140.435 Towing vessels |
Capability standard. Three outcomes, no item list, no quantities[1] | The operator. You choose the contents and you defend the choice |
| 46 CFR 28.210 Commercial fishing |
Contents driven, with a table of required items and a first aid training obligation[8] | The rule. Match the list and you are compliant |
| Directive 92/29/EEC EU flagged vessels |
Categories A, B and C, each with a defined annex of medicines and equipment[10] | The annex. The category follows the voyage |
A contents list is easier to satisfy and easier to inspect. A capability standard is easier to satisfy badly. If a boarding officer opens the cabinet on a coastwise unit and there is no cuff, the finding writes itself. If there is a cuff nobody has calibrated, no splint that fits an adult femur and a box of small adhesive dressings labelled as the means to apply large bandages for serious wounds, the finding is a judgement call, and judgement calls go against the party with no documented reasoning. The full contents logic for a chest that has to satisfy a list is set out in how to stock a chest, and the fishing comparison in the 28.210 rules.
Four things Subchapter M does not require
Getting the negatives right matters as much as the positives, because operators buy things they do not need and skip things they do.
- No medicine chest. The rule says first aid cabinet or kit[1]. A medicine chest obligation, where one exists, comes from a flag state, a class society or a charter clause, and never from part 140.
- No medical guide or reference publication. That requirement belongs to international instruments, not to Subchapter M. What a port state control officer actually looks for under those instruments is set out in the inspection checklist.
- No designated medical person and no medical training beyond the general subpart E obligation. Part 140 requires training in the health and safety requirements of that subpart[5] and emergency drills and instruction[7], but it names no medical care provider role.
- No controlled substances, and no permission to carry them. Subchapter M is silent, which is not the same as authorising. Scheduled drugs are governed by DEA rules whatever the vessel type, starting with the schedules and the record set in recordkeeping aboard a vessel.
Why the search results are wrong before you read them
A live capture of the first page for this query in August 2026 returned nine results and not one of them was a United States source. The page was filled by an EU legal database, a WHO guide, a Japanese class society, the Australian maritime authority, an IMO rules aggregator and a UK tug operator. The generated summary above the results described the two capability tiers accurately but sourced them to an International Labour Organization database rather than to the Code of Federal Regulations, and added a requirement for an up to date medical guide that appears nowhere in Subchapter M. An American towing operator searching this phrase is being answered with foreign law.
Where the rest of the medical duty actually lives
140.435 is the only equipment section, but it is not the only place part 140 touches medical matters. Four other sections carry obligations that surface in an audit, and one of them contains a duty most operators have never read.
| Section | What it obliges | The part that gets missed |
|---|---|---|
| 140.505(a) | Procedures for reporting unsafe conditions, and records of health and safety incidents on board including any associated medical records[2] | On request, the owner or managing operator must give a crewmember the incident report and that crewmember’s own associated medical records[2] |
| 140.505(d) | PPE available, suitable for the service, and meeting 29 CFR part 1910 subpart I, with training in its use, limitations and care[2][9] | Subchapter M reaches into the OSHA rulebook here. The same crossover decides the injury reporting threshold |
| 140.515 | Training in the health and safety requirements of subpart E[5] | Training records are the evidence, and 140.915 governs what is recorded[12] |
| 140.900 | Comply with 46 CFR part 4 for reporting marine casualties and retaining voyage records[4] | Every injury question is handed to part 4, where the reporting threshold is a two part test[11] |
The medical records access duty in 140.505(a) is the sleeper. It is a records obligation with a privacy shape, and a company that keeps incident paperwork in a shared operations folder cannot satisfy it cleanly. Where responsibility for that sits in a shore organisation is the subject of owner or designated person, and the wider structure in the six decisions.
Who checks it depends on a choice you already made
46 CFR 136.130(a) gives two routes to a Certificate of Inspection: the Coast Guard option, in which all inspections are conducted by the Coast Guard, and the TSMS option[3]. That choice was made at the fleet level, usually years ago, and it decides who opens the first aid cabinet first.
Under the Coast Guard option the marine inspector is the first reader of the kit. Under the TSMS option a third party auditor is, and the finding lands inside your own safety management system before it ever reaches a government file. Operators sometimes read the second route as softer. It is not. An auditor working to a management system asks the question a capability standard invites, which is not “is there a splint” but “show me why this is appropriate to the size of the crew and operating conditions”. The same question, and the same evidence gap, is what a compliance audit is built to surface, and the master and crew duties that sit alongside it are in 140.210[6].
Building a kit you can defend
A capability standard is satisfied by a documented argument, not by a purchase order. Five steps produce that argument, and none of them requires buying more than you already should.
- Write the route determination first. Oceans, coastwise or Great Lakes triggers the second tier[1]. Record which routes each hull is certificated for and which tier follows. This is one line per vessel and it removes the most common finding.
- Map each of the three capabilities to named items. Blood pressure measurement, fracture immobilisation, large wound dressing. One page, item by item, so the answer to “what is your means” is a document rather than a rummage.
- Size the baseline kit against crew and operating conditions, in writing. The phrase is in the rule, so the reasoning belongs in the file. Crew number, watch pattern, distance and time to shoreside care. The method for the last one is in planning by voyage length.
- Set an expiry and restock cycle with an owner. Nothing in 140.435 mentions expiry, which is exactly why it is the finding that recurs. Fishing operators face the same problem under a stricter rule, described in the six federal obligations.
- Decide in advance who is called and when. Part 140 gives no clinical support structure, so the operator supplies it. The framework for that decision is in who decides an evacuation.
Step two is the one that converts an inspection from an argument into a reading, because it replaces a rummage through a cabinet with a page an auditor can read. If you want the reasoning written and the kit specified against your actual routes, that is maritime medical consulting and chest management. Everything else sits in the guidance library, and the physician behind it is on the about page.
Common questions
Does Subchapter M require a towing vessel to carry a medicine chest?
No. 46 CFR 140.435 requires an industrial type first aid cabinet or kit, not a medicine chest. Medicine chest obligations come from a flag state, a class society or a charterer, not from Subchapter M. The flag state picture is set out in requirements by flag state.
What is the difference between the baseline kit and the route based requirement?
Every towing vessel needs the industrial first aid cabinet or kit sized to the crew and operating conditions. Vessels operating on oceans, coastwise or Great Lakes routes must additionally have a means to take blood pressure readings, splint broken bones and apply large bandages for serious wounds. The second tier is triggered by route, not by tonnage or crew size. Route driven planning is covered in planning by voyage length.
Does 140.435 tell me what to put in the kit?
It does not. The section names outcomes and leaves the contents to the operator, which is the opposite of how 46 CFR 28.210 treats commercial fishing vessels. The practical consequence is that the burden of showing the kit is appropriate sits with you rather than with a published list.
Can a towing vessel carry controlled substances under Subchapter M?
Subchapter M is silent on controlled substances, which means it neither authorises nor prohibits them. Anything in a federal schedule is governed by DEA rules regardless of vessel type. Start with what the schedules mean aboard a vessel and 21 CFR 1301.25.
Who inspects the first aid kit, the Coast Guard or a third party auditor?
That depends on the compliance route chosen for the Certificate of Inspection. 46 CFR 136.130 sets out two options, the Coast Guard option and the TSMS option. Under the TSMS option a third party auditor sees the kit first. Either way the evidence expected is the same, which is what an audit actually checks describes.
Does Subchapter M require a medical guide or reference publication on board?
No. Search results frequently attribute a publication requirement to towing vessels, but it comes from international instruments rather than from Subchapter M. The instrument that does require a medical guide is the ILO Maritime Labour Convention, covered in what a port state control officer checks.
An injury happened on board. What does Subchapter M require me to do?
46 CFR 140.900 hands the question to 46 CFR part 4, so the towing rules themselves add nothing. The threshold that decides whether it is reportable is explained in the beyond first aid test. Separately, 140.505(a) requires the health and safety incident record and any associated medical records to be kept.
