The short version
- 21 CFR 1301.25 covers any vessel engaged in international trade, with no US flag qualifier.
- The master requisition for controlled substances must state the vessel’s official number and country of registry.
- 46 CFR 4.03-1 defines a marine casualty around the navigable waters of the United States, not the flag.
- 42 CFR 71.21 binds the master of a ship destined for a US port, so the duty runs at sea.
- A port state inspection can be fully satisfied while all three US duties remain unaddressed.
Flag state compliance does not travel into a US port
The standard answer given to a foreign flag operator is that the flag state sets the medical rules and the port state checks the certificates. That is true for the certificates. It is wrong about three separate US federal regimes that attach the moment the vessel arrives.
None of them asks what flag the ship flies. Each is written around a different trigger: the voyage, the water, or the cargo in the chest.
| US regime | What triggers it | Does the flag matter? |
|---|---|---|
| 42 CFR 71.21 CDC death and illness report |
A ship destined for a US port[1] | No. Written around the destination |
| 46 CFR 4.03-1 Marine casualty, and the testing that follows |
A casualty involving any vessel other than a public vessel on the navigable waters of the United States[2] | No. Written around the water |
| 21 CFR 1301.25 DEA controlled substances aboard |
A vessel engaged in international trade[3] | No. Written around the trade |
A Port State Control examination checks whether the ship meets the international instruments it is certified against.[4] It does not tell the master that a fever aboard, an injured deckhand, or a morphine ampoule bought in Houston each sit inside a different American rulebook.
The DEA rule names the country of registry, so it clearly expects you
This is the one that surprises operators most, and the text removes any doubt.
21 CFR 1301.25(a)(1)
Controlled substances may be held for stocking, maintained in, and dispensed from medicine chests, first aid packets or dispensaries “on board any vessel engaged in international trade or in trade between ports of the United States and any merchant vessel belonging to the U.S. Government.”[3]
Any vessel engaged in international trade. There is no US flag qualifier in that sentence.
And when there is no DEA registered medical officer, the master or first officer may buy controlled substances from a registered vendor by written requisition. The regulation lists what that requisition must contain, and the list includes the vessel’s official number and country of registry.[3] A rule written only for US ships would not need to ask.
The mechanics of that purchase are set out in the medical officer and master requisition routes, and the paperwork that follows is in the recordkeeping duty. A foreign flag operator restocking in a US port is inside both. Our controlled substances service exists for exactly this transaction.
Where operators get it wrong
Buying narcotics ashore in a US port and treating it as a local purchase. It is a DEA transaction. The vendor files a copy of the record of sale with the nearest DEA Division Office within 15 days after the end of the month in which the sale is made.[3] The paperwork exists whether or not the ship keeps its copy.
An injury in US waters is a US marine casualty
46 CFR 4.03-1 defines a marine casualty as, among other things, any casualty or accident involving any vessel other than a public vessel that occurs upon the navigable waters of the United States, its territories or possessions.[2]
Read what is not there. No flag limitation. The definition then lists the events it covers, and the first is “any fall overboard, injury, or loss of life of any person.”[2]
A separate limb reaches further out for one class: a foreign tank vessel operating in waters subject to US jurisdiction, including the Exclusive Economic Zone, where there is significant environmental harm or material damage affecting seaworthiness.[2] Foreign tanker operators should read that alongside the chemical tanker antidote rule.
Once the event is a marine casualty and meets the medical threshold, the serious marine incident testing regime engages and the alcohol clock is two hours.[5] That threshold is conjunctive: treatment beyond first aid and unfitness for routine duties, which is the same test explained in the reporting threshold article.
The CDC duty starts before you arrive, not on arrival
42 CFR 71.21 places the duty on the master of a ship destined for a US port, which means it is running while the vessel is still at sea.[1] The report goes to the quarantine station at or nearest the port of arrival, and it covers any death and any ill person as that term is defined in 42 CFR 71.1.[6]
The full walkthrough of the CDC duty sets out the definition, including the temperature threshold and the limbs that make a person reportable. Two things matter for a foreign flag master.
- Reporting to the Coast Guard does not discharge it. These are separate agencies with separate duties.
- The clock is immediate, not on arrival. A report made at the pilot station is already late if the illness appeared three days earlier.
Where the illness ends in a death aboard, the US death on board procedure adds custody and documentation steps that flag state guidance does not cover.
What the port state actually inspects, and what it does not
MLC 2006 gives a port state the power to inspect medical care on board a foreign ship, and the certificates it checks are issued by the flag.[7] That is a compliance check against an international standard, not against Title 21, Title 42 or Title 46 of the US code of federal regulations.
| Question | Answered by the flag state | Answered by US law |
|---|---|---|
| What is in the medicine chest | Yes. Flag rules and MLC A4.1[7] | No US contents list exists[8] |
| Who may buy narcotics in a US port | No | Yes. 21 CFR 1301.25[3] |
| Who must be tested after an injury in US waters | No | Yes. 46 CFR 4.03-1 and subpart 4.06[2][5] |
| Who must be told about a fever aboard | No | Yes. 42 CFR 71.21[1] |
The gap in the middle column is the point. A flag state inspection can be fully satisfied while all three US duties remain unaddressed, because nobody at the flag has any reason to raise them. The comparison of flag chest rules shows how far apart the registers already are before US law is added.
The chest that satisfies your flag may still be a US problem
A chest built to a European or Asian register can contain items that are prescription only or scheduled in the United States. The chest is not illegal for being aboard. The exposure is created by what happens next: restocking, disposal, and any transfer ashore.
The schedule question decides which items pull the vessel into the DEA regime at all, and disposal is where a foreign flag operator most often improvises. Expired narcotics do not go over the side and do not go in a US port skip.
Fleets that change flag inherit a new contents standard, but the US regimes described here do not change with it, because none of them is keyed to the flag. Our ship medical chest management service maps the flag standard and the US overlay as two layers on one inventory.
Who carries this ashore
On a foreign flag vessel these duties usually land on an agent who handles ten ships and a superintendent who is in another time zone. The owner and DPA split decides who owns them, and the programme setup is where they get written down before the first US call rather than during it.
Vessels calling irregularly are the highest risk, because nothing recurs often enough to become routine. Planning by time to definitive care applies at sea, and the US port call needs its own short annex.
Six checks before the next US call
- List every controlled substance in the chest against US schedules, not only against your flag’s classification.[3]
- Decide the restock route now. DEA registered medical officer, or the master requisition, with the official number and country of registry ready.[3]
- Write the CDC reporting step into the arrival checklist, with the quarantine station contact for each port you call.[1]
- Brief the master on the conjunctive injury test, because that judgement starts a two hour testing clock in US waters.[2][5]
- Confirm who ashore owns each duty and name them, agent or superintendent.
- Never dispose of scheduled drugs in a US port without the route documented.[9]
Discovery Health MD is led by Ann Jarris MD, MBA, FACEP, a board certified emergency physician, and works with foreign flag operators calling US ports as well as US flag fleets. Mapping a flag standard onto the American overlay is exactly what our maritime medical consulting line does, and the audit walkthrough shows how it is checked. Speak to the team.
Common questions
Do US medical rules apply to a foreign flag vessel?
Three of them do, and none is keyed to the flag. 42 CFR 71.21 places a death and illness reporting duty on the master of a ship destined for a US port[1]. 46 CFR 4.03-1 defines a marine casualty to include any casualty involving any vessel other than a public vessel occurring upon the navigable waters of the United States[2]. 21 CFR 1301.25 governs controlled substances on board any vessel engaged in international trade[3]. Flag state compliance answers none of the three.
Can a foreign flag ship buy controlled substances in a US port?
Yes, through the routes in 21 CFR 1301.25, and the regulation clearly contemplates foreign vessels. Where no DEA registered medical officer is employed, the master or first officer may purchase from a registered manufacturer, distributor or authorised pharmacy using a written requisition on the vessel’s stationery, and that requisition must include the vessel’s official number and country of registry[3]. The vendor forwards a copy of the record of sale to the nearest DEA Division Office within 15 days after the end of the month of sale.
Is an injury on a foreign flag vessel in US waters a US marine casualty?
Yes. 46 CFR 4.03-1(1)(i) defines a marine casualty as any casualty or accident involving any vessel other than a public vessel that occurs upon the navigable waters of the United States, its territories or possessions, and the listed events begin with any fall overboard, injury, or loss of life of any person[2]. If the injury requires professional medical treatment beyond first aid and renders the person unfit for routine duties, the serious marine incident testing regime in 46 CFR subpart 4.06 engages and alcohol testing has a two hour deadline[5].
Does reporting to the Coast Guard satisfy the CDC requirement?
No. They are separate duties owed to separate agencies. 42 CFR 71.21 requires the master of a ship destined for a US port to report the occurrence on board of any death or any ill person to the quarantine station at or nearest the port of arrival[1], with ill person defined in 42 CFR 71.1[6]. A Coast Guard casualty report under 46 CFR part 4 does not discharge it, and the CDC duty is running while the vessel is still at sea.
Does a Port State Control inspection cover these US rules?
No. Port State Control verifies compliance with the international instruments the ship is certified against, and MLC 2006 allows inspection of medical care on board[4][7]. That is a check against an international standard and the flag state’s certificates. It is not a check against 21 CFR, 42 CFR or 46 CFR, so a foreign flag vessel can pass a port state inspection with all three US duties unaddressed.
What should a foreign flag operator do about the medicine chest before a US call?
Screen the contents against US drug schedules rather than the flag’s classification. A chest built to a European or Asian register may hold items that are prescription only or scheduled in the United States, and the exposure appears at restocking, disposal or transfer ashore rather than at carriage. Decide the restock route in advance, and never dispose of scheduled drugs in a US port without a documented route[3][9].
Who ashore is responsible for these duties on a foreign flag ship?
It has to be assigned, because it does not assign itself. On foreign flag vessels these obligations typically fall between a port agent handling many ships and a superintendent in another time zone. The MLC and ISM framework puts accountability with the owner and the designated person ashore, and the practical answer is to name the owner in a short US port call annex to the medical programme before the first call rather than during it.
