The short version
- 92/29/EEC scales by 150 nautical miles to the nearest port with adequate medical equipment, not to the nearest land.
- MLC 2006 scales by three days of voyage for both its doctor and sick bay thresholds.
- 46 CFR 28.210 scales by nothing. It asks for a chest suitable for the number of individuals on board and stops.
- The variable that survives all three is time to definitive care, and no regulation asks you to calculate it.
- Radio medical advice is a free obligation on ratifying states. The US has ratified neither instrument, so write your own route.
Every instrument that scales a vessel’s medical capability scales it by a different unit, and none of them scales it by the thing that actually decides outcomes. Europe measures nautical miles. The MLC measures days. US fishing law measures nothing at all. What matters at sea is how long it takes to get a person to definitive care, and no regulation asks you to calculate it.
That gap is not a loophole to exploit. It is the single most defensible thing a remote operator can put in writing.
Three instruments, three different units
Put them side by side and the incoherence is obvious. Each is internally sensible. Together they give an operator working a long passage no single answer.
| Instrument | What it scales by | The actual test |
|---|---|---|
| EU Directive 92/29/EEC | Distance | Category B is trips of less than 150 nautical miles from the nearest port with adequate medical equipment. Category A has no limitation on length of trips[1] |
| MLC 2006 | Days and headcount | A doctor at 100 or more persons on an international voyage of more than three days[2] |
| 92/29/EEC, sick bay | Tonnage, crew and days | Over 500 gross tons, 15 or more crew, voyages exceeding three days[1] |
| 46 CFR 28.210(a) | Nothing | “A size suitable for the number of individuals on board.” No distance, no duration, no contents[3] |
Read the first row carefully, because it is the one most often misquoted. The 150 miles is measured to a port with adequate medical equipment, not to the nearest landfall[1]. A vessel working 120 miles off a coast with no equipped port inside that arc is functionally further from care than one 200 miles from a major port. The full category breakdown is in the 92/29/EEC article.
Plan against the self-sufficiency window
The variable that survives across all three regimes is the one none of them names: how many hours the vessel must manage a serious problem alone. Call it the self-sufficiency window, compute it honestly, and everything downstream becomes a decision rather than a guess.
What goes into the window
Four inputs, and only the first is a chart problem. Distance to the nearest port with adequate medical capability, not the nearest port. Realistic transit or extraction time in the weather you actually work, not in a flat calm. The hours before an extraction can even launch. And the time a shore physician needs to be reached and to respond[1].
The output is a number of hours, stated as a range, written down and signed. That single figure is what a sizing method is built on, and it is what turns an undefined obligation into a defensible one. The sequence it belongs to is in the six decisions, and for a US operation with no federal list at all the reasoning is set out in the 28.210 rules.
What changes as the window lengthens
Capability does not scale linearly with hours. It steps, and the steps are about what the vessel must be able to hold rather than what it must be able to cure.
| Self-sufficiency window | What the vessel must be able to do | Where the planning effort goes |
|---|---|---|
| Under 6 hours | Stabilise and hand over | Speed of the escalation call. The chest is a bridging tool |
| 6 to 24 hours | Stabilise, then maintain through a night and a weather window | Analgesia, fluids and a documented handover. Quantities begin to matter more than range |
| 1 to 3 days | Treat a defined problem to a conclusion, or hold it | Range of the chest, and the competence of the person using it. This is where the MLC three-day thresholds sit[2] |
| Beyond 3 days | Run a small clinic with no resupply | Depth, redundancy and expiry management. Category A logic, whatever your flag[1] |
Anchor the quantities to a published reference once the band is chosen. The WHO Quantification Addendum of 2010 carries recommended quantities, indications and dosing and is the most usable anchor in print[5]. It is guidance, not law, and there is no fourth edition of the guide it accompanies[6].
The capability you should not be buying
Remote planning conversations turn quickly to who you call. Before that becomes a purchase, note where the obligation actually sits. MLC Standard A4.1(4)(d) requires ratifying states to ensure medical advice by radio or satellite is available free of charge, and 92/29/EEC requires Member States to designate centres providing free advice by radio[2][1].
The United States has ratified neither instrument, so a US-flagged vessel gets no treaty guarantee and has to establish and document its own route. That is a writing job, not a subscription. What it should produce is one page on the bridge: who is called, on what number, in what order, and who decides to divert. The full decision is decision four of six.
Distance changes nothing about the drug file, and makes one part harder
It is tempting to assume a remote voyage justifies a deeper controlled substance holding. Section 1301.25 reads identically on day one and day forty[7]: the medical officer must be licensed, DEA-registered and employed by the owner or operator, or the master requisition route applies.
Distance does make one thing materially harder. Disposal routes overwhelmingly require a registered location ashore, so expired stock accumulates on a long deployment and leaves the vessel only in port. Plan the return leg for it. See disposal from a ship chest, plus 1301.25 explained, the two routes, recordkeeping, schedules, the annual reports and the inspection checklist.
Four lines that make a remote voyage defensible
- State the window in hours, as a range. Distance to an equipped port, realistic transit in working weather, launch delay, physician response[1].
- Name the band and the reference. Which row of the table above, and which published source the quantities came from[5].
- Check the two three-day thresholds against the actual voyage plan, even if you expect to clear them easily[2].
- Write the escalation route and the disposal plan on the same page. One is needed at 3am, the other on the way home[7].
Line one carries everything. An operator who can state the window and show how it was derived has answered a question no regulation asked and every inspector respects. For fishing fleets the federal baseline sits in the six obligations, and the Alaska layer in Alaska compliance.
MedChest builds to the window and consulting derives it with you.
Common questions
How do I decide how much medical capability a voyage needs?
Start from time to definitive care, not from distance. Every instrument that scales capability uses a different unit: 92/29/EEC scales by 150 nautical miles to the nearest port with adequate medical equipment[1], MLC uses three days of voyage for its doctor and sick bay tests[2], and US fishing rules use nothing at all[3]. Our consulting service converts them to one number.
Why is distance a poor planning variable on its own?
Because the Category B test is not a distance to land, it is a distance to a port with adequate medical equipment[1]. A vessel 120 miles off a coast with no equipped port inside that arc is further from care than a vessel 200 miles from a major port. Weather, sea state and helicopter range then move the answer again. See the EU categories in full.
Does any regulation ask me to calculate time to definitive care?
None of them do, which is exactly why it is the planning variable worth owning. 92/29/EEC requires quantities to reflect the nature of the voyage, the type of work, the cargo and the number of workers[1], and 46 CFR 28.210(a) asks only for a chest “of a size suitable for the number of individuals on board”[3]. The gap is yours to fill in writing. We write it with you.
What thresholds actually change with voyage length?
Two, and both use three days. A doctor is required at 100 or more persons on an international voyage of more than three days, and 92/29/EEC adds a sick bay for vessels over 500 gross tons carrying 15 or more crew on voyages exceeding three days[1][2]. Almost no commercial fleet reaches the doctor threshold, which is the point.
Is telemedical support a legal requirement?
The obligation is on states, not on you, and it is free where it applies. MLC Standard A4.1(4)(d) requires ratifying states to ensure free 24-hour radio or satellite medical advice, and 92/29/EEC requires Member States to designate centres giving free advice by radio[2][1]. The United States has ratified neither, so a US-flagged vessel writes its own escalation route. See decision four.
How should quantities scale for a long passage?
Against a documented self-sufficiency window rather than a multiplier. Anchor the quantities to the WHO Quantification Addendum, then state the window you sized for and why[5]. There is no fourth edition of the WHO guide[6]. Build it per the stocking guide.
Does remoteness change the controlled substance position?
Not one line of it. 21 CFR 1301.25 applies the same on day one and day forty[7], and disposal still requires a registered location ashore, which is harder the further out you work. See disposal from a ship chest and 1301.25 explained.
