The short version
- US law already requires a medical log on many vessels, and it is not a product you buy. It is the official logbook under 46 U.S.C. 11301[1].
- The statute requires an entry for “each illness of or injury to a seaman of the vessel, the nature of the illness or injury, and the medical treatment”[1].
- It also requires an entry for “each death on board, with the cause of death”[1].
- Entries must be made as soon as possible after the occurrence, and signed by the master and the chief mate or another seaman[2].
- Anything that happened before arrival must be entered within 24 hours of reaching the final port of discharge[2].
- Penalties: $200 for failing to keep the logbook, $200 for a missing entry, $150 for a late one[3].
Search results for this sell you a book. The law gives you a form
Search ship medical log book requirements and page one offers logbook products, a template on a document-sharing site, a class society circular and the WHO guide. The United States Code sits there too, and no ranking page reads it.
That matters because US-flag operators are buying a commercial medical logbook while leaving blank the statutory entries a Coast Guard investigator will actually ask for. The product is optional. The statute is not.
46 U.S.C. 11301(b), Official logbooks
The master shall record “each illness of or injury to a seaman of the vessel, the nature of the illness or injury, and the medical treatment”, and “each death on board, with the cause of death”[1].
Which US vessels must keep one
The trigger is trade, not tonnage alone. 46 U.S.C. 11301(a) requires an official logbook on a vessel of the United States that is on a voyage from a US port to a foreign port, or that is at least 100 gross tons and on a voyage between a US Atlantic port and a US Pacific port[1].
Note what that does and does not catch. A foreign voyage triggers it at any size, which is the same axis as the medicine chest statute in 46 U.S.C. 11102[4]. A purely coastwise run on one seaboard does not.
| Voyage | Official logbook required? | What still applies |
|---|---|---|
| US port to foreign port | Yes, any size[1] | Medicine chest under 46 U.S.C. 11102[4] |
| Atlantic to Pacific, 100 GT or more | Yes[1] | Same statute, same axis |
| Coastwise on one seaboard | No | Casualty reporting and testing duties still bite[6] |
| US fishing vessel | Usually no | 46 CFR part 28 first aid duties apply regardless[11] |
| Any vessel bound for a US port | Separate question | 42 CFR 71.21 illness report applies to all[5] |
The two medical entries, read closely
Paragraph (b) lists thirteen categories. Two are medical and both are written more broadly than crews assume[1].
The illness entry covers each illness or injury, not each serious one. There is no threshold in the statute, no first aid carve-out and no reference to lost time. It also demands three things in one entry: the fact, the nature, and the treatment given[1]. An entry reading “crew member unwell, rested” satisfies none of them.
The death entry requires the cause of death[1]. A master is not a medical examiner, which is exactly why the entry should record the clinical picture and the advice received rather than a conclusion. The wider procedure sits in death on board a vessel, and the estate side is governed separately by 46 U.S.C. 11104[12].
Timing and signatures, where most entries fail
46 U.S.C. 11302 sets the mechanics. Each entry shall be made as soon as possible after the occurrence, and if not made on the day of the occurrence, shall be dated and state the date of the occurrence[2]. Entries about anything that happened before arrival must be made not later than 24 hours after the vessel reaches the final port of discharge[2].
The signature rule is the one that quietly voids entries. Each entry must be signed by the master and by the chief mate or another seaman[2]. A single signature is not an entry, it is a note.
| Failure | Statutory penalty | Who is liable |
|---|---|---|
| No official logbook maintained | $200 civil penalty[3] | The master[3] |
| Required entry not made | $200 civil penalty[3] | The master, per entry[3] |
| Entry made late | $150 civil penalty[3] | Any person who makes, procures or assists the entry[3] |
The sums are small and the exposure is not. A logbook with gaps is the first document produced in a casualty investigation, a crew claim or a records request, and the gaps do the damage rather than the fine.
The other eleven categories, and why the medical two sit inside them
46 U.S.C. 11301(b) is one list of thirteen categories, and reading it whole explains why the medical entries are written the way they are[1]. Alongside illness, injury and death it requires entries for convictions and punishments of seamen, the conduct and character of each seaman, births and marriages on board, seamen ceasing to be crew, wages due to a deceased seaman, the sale of a deceased seaman’s property, marine casualty statements and ballast water management failures[1].
That is a crew status register, not a clinical chart. The statute is tracking who was aboard, what happened to them and what the vessel owed them. The medical entries exist to answer a later question about liability and welfare, which is why the nature of the illness and the treatment given both have to be there[1].
It also explains an overlap operators trip on. A death on board generates a logbook entry under (b)(6), a wages entry under (b)(10), a property entry under (b)(11), an account under 46 U.S.C. 11104[12], a CDC report before a US arrival[5], and a casualty statement[6]. One event, six records, and the logbook is the only one that ties them together.
What the official logbook is not
Three records get confused with it, and each has its own rule.
- The controlled substances record. Scheduled medication in the chest is governed by 21 CFR 1301.25 and the recordkeeping rules in 21 CFR 1304.04[7][8]. Schedule II records are kept separately from III to V, and the aboard copy is its own document. See controlled substances recordkeeping.
- The CDC report. 42 CFR 71.21 requires a report to the quarantine station before arrival at a US port[5]. Writing it in the logbook does not make the report.
- The crew medical file. Employment-side medical records are a separate holding with separate access rules, covered in crew medical records on a US vessel.
Making the entries survive an investigation
Write the entry as if a third party will read it two years later with no memory of the voyage, because that is what happens. Record the time, the presentation, the advice sought and from whom, the treatment given including anything drawn from the chest, and the outcome[1]. Where the chest supplied a scheduled drug, the logbook entry and the controlled substances record must agree[7].
Clinical wording matters here. A physician-reviewed entry reads differently from a deck note, and that difference is visible to an investigator. Scope the underlying chest against your flag state and the WHO International Medical Guide for Ships[9], and remember that for foreign-flag tonnage the MLC medical record requirement runs alongside this one[10].
Discovery Health MD builds the record structure and the clinical advice behind it. Programme design sits in maritime medical consulting, the chest in MedChest, and scheduled medication in controlled substances management. Start with the six decisions or a compliance audit. Speak to the team.
Common questions
Is a ship medical log book required by US law?
There is no separate medical logbook in US law. The requirement sits inside the official logbook under 46 U.S.C. 11301, which obliges the master to record each illness or injury to a seaman, its nature and the medical treatment, and each death on board with the cause[1]. Commercial medical logbooks are useful formats, but the legal duty attaches to the official logbook.
Which vessels must keep an official logbook?
A vessel of the United States on a voyage from a US port to a foreign port, at any size, or a vessel of at least 100 gross tons on a voyage between a US Atlantic port and a US Pacific port[1]. Note the foreign voyage trigger matches the medicine chest statute, so a vessel that owes a chest usually owes a logbook[4].
How soon must a medical entry be made?
As soon as possible after the occurrence[2]. If it is not made on the day it happened, it must be dated and state the date of the occurrence[2]. Anything that occurred before arrival must be entered no later than 24 hours after the vessel reaches the final port of discharge[2].
Who has to sign a logbook entry?
The master and either the chief mate or another seaman[2]. Two signatures, not one. This is the most common defect we see because whoever provided care often writes the entry and never countersigns, leaving the record open to challenge in a casualty investigation.
What is the penalty for a missing entry?
A master failing to maintain the official logbook is liable for a $200 civil penalty, and a master failing to make a required entry is liable for a further $200[3]. A late entry carries $150, and that one reaches any person who makes, procures or assists it, not only the master[3]. The real cost is evidential rather than financial.
Does a minor injury have to go in?
The statute says each illness of or injury to a seaman[1]. It sets no severity threshold and no first aid exception. That is a different test from the Coast Guard reporting threshold, which does turn on whether treatment went beyond first aid. Two standards, two records, and confusing them is how logbook gaps appear.
Can the logbook double as the controlled substances record?
No. Scheduled medication aboard is governed by 21 CFR 1301.25 and the recordkeeping rules in 21 CFR 1304.04[7][8], which require their own records with their own retention and their own separation between Schedule II and Schedules III to V. The two records must agree, and the schedule determines the record, but neither replaces the other.
