The short version
- Subchapter L contains no first aid, medicine chest or medical equipment requirement for the vessel itself. Checked across parts 125 to 135.
- The only first aid kit it names is survival craft and rescue boat equipment at 46 CFR 133.175, described by reference to 46 CFR 199.175.
- The duty to log an illness, injury or death arrives through 131.630, which pulls in 46 USC 11301. It is not in the 131.620 list.
- Casualty reporting still applies in full through 131.110 and 46 CFR part 4.
- Search results for this question are answered with the UK ENG1 certificate, EU chest categories and Australian guidance. No United States source ranks.
Google answers this question with a British medical certificate
A live capture of the first page for this question in August 2026 returned nine results and not one of them was a United States source. A Dutch training provider, an EU medical chest supplier, the World Health Organization ship guide, the Australian maritime authority, an ILO record concerning Dutch sea-going vessels, a United Kingdom medical kit page, a Marshall Islands circular, a shipping blog and a UK training school.
The generated summary at the top of the page led with the ENG1, a seafarer medical certificate issued by the United Kingdom Maritime and Coastguard Agency. For an operator running platform supply vessels out of Fourchon or Galveston, that answer is not merely unhelpful. It describes a document that does not exist in their regulatory world.
| What the page says | Where it comes from | What Subchapter L actually says |
|---|---|---|
| Crew medical fitness certificates, ENG1 | UK MCA | Nothing. Subchapter L contains no crew medical certification section[1] |
| Onboard medical chest by category | EU and flag state regimes | Nothing. No medicine chest section exists in parts 125 through 135[1] |
| Trained medical personnel | MLC and flag state rules | Nothing. No designated medical care provider role appears anywhere in the subchapter[1] |
The absence is real, and it was checked part by part
Claims that a regulation contains nothing deserve more evidence than claims that it contains something, so this one was verified across the whole subchapter rather than inferred from one part.
| Part | Subject | Medical content |
|---|---|---|
| 125 to 130 | General, inspection and certification, construction and arrangements, marine engineering, electrical, vessel control[1] | None |
| 131 | Operations. Nine subparts covering casualty notice, markings, emergency preparations, survival craft crews, tests and drills, logs, work vests, equipment markings and miscellaneous[2] | None |
| 132 and 134 | Fire protection equipment, added provisions for liftboats[1] | None |
| 133 | Lifesaving systems[3] | One reference only, at 133.175, and it is not about the vessel |
That is a whole subchapter governing a fleet that works fifty to a hundred and fifty miles offshore, and the medical content is a single line inside a lifesaving equipment table.
The one kit Subchapter L requires, and where it lives
46 CFR 133.175 sets out the equipment for survival craft and rescue boats, and states that each item in its table has the same description as in 46 CFR 199.175[3]. A first aid kit appears in that table for rigid lifeboats on oceans and coastwise routes and for rescue boats.
Why this is the most misread line in the subchapter
Operators read “first aid kit required” and stop. The kit in 133.175 is survival craft equipment. It lives in the boat, it is stocked for people who have abandoned the vessel or are recovering someone from the water, and its contents are described by reference to a lifesaving standard rather than to any clinical need on deck. A crewmember with a crush injury in the engine room is not the person that kit was written for. Treating it as the vessel’s medical provision leaves you with no medical provision and an opened survival kit.
The item description chain runs through 46 CFR 199.175[4], which is the same section the small passenger vessel rules point at, and which terminates in a purchased ISO standard. That route is walked through in the Subchapter T article.
The record duty arrives through a statute, not through the subchapter
This is the mechanism most OSV operators have never traced, and it matters because it is the one medical obligation that is genuinely enforceable against an OSV.
46 CFR 131.620 lists the matters that must be logged: safety orientation for offshore workers, steering gear and whistle and communications tests, draft and loadline markings, stability verification, periodic sanitary inspections, hatches and openings, emergency lighting and power tests, abandon ship and firefighting drills, and lifeboat winch inspections. Nine items, none of them medical[5].
Then 131.630 does the work. On each vessel required to have an Official Logbook, the items required by 46 USC 11301 must be entered as well as the items in 131.620[6]. And 46 USC 11301(b) requires an entry for each illness of or injury to a seaman, the nature of it and the medical treatment given, and for each death on board with the cause[7].
So the medical record duty is real, and it enters through a cross reference to a statute rather than through anything Subchapter L says about medicine. An operator reading only the subchapter will never find it. The wider records position, including who is entitled to see those records, is set out in crew medical records.
What actually fills the gap
Four things reach an OSV where the subchapter does not, and three of them are not regulation at all.
- Casualty reporting. 46 CFR 131.110 carries notice and voyage record duties[8], and the substantive thresholds sit in 46 CFR part 4[9]. What counts as a reportable injury is examined in the beyond first aid article, and the sequence after a death in the death on board procedure.
- The charterer. Offshore operators routinely impose medical contents, training and response time requirements through contract. Because there is no federal floor, that clause frequently becomes the only written standard on the vessel.
- Distance. An OSV working a deepwater field is hours from shore by helicopter and longer by sea. Nothing in the CFR accounts for that, so the operator has to. The method is in planning by voyage length and the decision framework in the evacuation article.
- Anything scheduled. Controlled substances are governed by DEA rules whatever the vessel class, starting with the schedules and recordkeeping aboard a vessel.
Setting a standard you can defend
With no rule to match, the deliverable is a written rationale. Four steps produce one.
- State plainly, in the manual, that Subchapter L sets no vessel medical standard. Naming the gap is what forces the next three steps to happen. Operators who never write it down keep assuming somebody else has.
- Borrow a floor and say which one you borrowed. The three United States classes that do have rules are compared in the vessel class comparison, and the towing capability standard at 140.435[10] transfers well to an offshore workboat. Fishing[12] and small passenger[11] are the other two reference points.
- Keep the rescue boat kit sealed and separate. One kit for survival craft, one for the vessel, each inventoried on its own line. This single change prevents the most common finding on an OSV, which is a survival kit that has been quietly emptied.
- Write the record route down. 131.630 to 46 USC 11301 is a two hop chain and nobody remembers it under pressure[6][7].
Step two is the one that converts an audit conversation. An operator who says “we hold to the Subchapter M capability standard because our routes and crew sizes are comparable, and here is the mapping” is in a stronger position than one working to a rule that binds them, because the reasoning is visible. If you want that standard set and documented for a fleet, that is maritime medical consulting and chest management, with the audit view in a compliance audit. The index is in the guidance library and the reviewing physician on the about page.
Common questions
Does Subchapter L require a first aid kit on an offshore supply vessel?
Not for the vessel. Parts 125 through 135 contain no section requiring a first aid kit, a medicine chest or medical equipment for the OSV itself. The only first aid kit named anywhere in the subchapter is the one carried inside survival craft and rescue boats under 46 CFR 133.175. How other United States classes are treated is compared in the vessel class comparison.
So we do not need a kit on board at all?
You need one. What you do not have is a federal specification telling you what it contains. Casualty reporting, crew safety and charterer terms all assume a functioning medical capability, and an operator with no written standard is in a weaker position than one working to a rule they can point at. The evidence question is the same one towing operators face, set out in the Subchapter M rules.
Why do search results tell me I need an ENG1?
Because no United States source ranks for this question. A live capture in August 2026 returned a Dutch training provider, an EU chest supplier, the WHO guide, the Australian maritime authority, an ILO record about Dutch vessels, a UK medical kit page and a Marshall Islands notice. ENG1 is a United Kingdom Maritime and Coastguard Agency seafarer medical certificate. It has no application to a Gulf of Mexico OSV.
Where does the duty to record an illness or injury come from, then?
Through a statute rather than through Subchapter L. 46 CFR 131.620 lists nine matters that must be logged and none is medical, but 131.630 requires vessels carrying an Official Logbook to enter the items required by 46 USC 11301, which include each illness or injury and the medical treatment given. The full records picture is in crew medical records.
What about reporting a serious injury or a death?
That runs through 46 CFR part 4 like every other commercial vessel. The injury threshold is a two part test explained in the beyond first aid article, and the sequence after a death is in the death on board procedure. Nothing in Subchapter L softens either.
Is the rescue boat kit the same as a vessel medical chest?
No, and treating it as one is a common and expensive error. It is survival craft equipment, described by reference to 46 CFR 199.175, sized and stocked for people in a liferaft or rescue boat. It is not designed for treating an injury on deck and it should not be raided for routine use. What a working chest looks like is in how to stock a chest.
Our charterer imposes its own medical standard. Does that override the CFR?
It does not override anything, it adds. A charterer or an offshore operator can impose contents, training and response time requirements far heavier than the CFR, and those are enforceable as contract terms. Because Subchapter L sets no floor, the charter clause often becomes the only written standard the vessel has. Where that sits in a programme is the six decisions.
