The short version
- No international convention requires an AED on a merchant ship. Unless the flag requires one, carrying it is optional[1].
- Germany has required AEDs on its seagoing merchant ships since September 2012[1][2]. Malta issued a notice in August 2025 calling for at least one marine-suitable AED[3].
- We found no general US Coast Guard carriage rule for AEDs. The federal law that does apply is a liability law, 42 U.S.C. 238q[5].
- Heart disease drives the case: cardiovascular conditions caused 58% of illness-related crew deaths in Britannia P&I claims data[6].
- Time is the variable. In one European program, AED volunteers arrived in 5.7 minutes against 10.2 for EMS, and good neurological survival was 46.2% against 2.9%[9].
No rule requires it. The numbers make the case anyway
A fleet manager asking whether an AED is required is asking the wrong question. For most flags the legal answer is no: Britannia P&I states that unless the flag administration mandates it, carrying an AED on a merchant ship remains optional[1].
The better question is what happens aboard when a crew member’s heart stops, and the data answers it plainly. On a ship, there is no ambulance coming in ten minutes. The defibrillator either sits in the ship’s hospital or it does not exist.
| Jurisdiction | Instrument | What it says |
|---|---|---|
| International (IMO, MLC) | No AED carriage rule | Optional unless the flag requires it[1] |
| Germany | Flag requirement | Required on seagoing merchant ships since September 2012[1][2] |
| Malta | MS Notice 198, 28 August 2025 | At least one AED suitable for marine conditions, crew trained, checks in planned maintenance[3] |
| United Kingdom | MGN 297 (M), October 2005 | Passenger ships to decide by risk assessment; consider one if likely to be used more than once in five years[4] |
| United States | No general Coast Guard carriage rule found | 42 U.S.C. 238q sets Good Samaritan liability rules for AED users and acquirers[5] |
What the flag states that act actually require
Germany moved first. A German study records it as the first flag state to legally require AEDs on seagoing merchant vessels, with September 2012 as the deadline[2].
Malta’s Merchant Shipping Notice 198 is the most recent. It calls for Malta-flag vessels, especially passenger vessels and those sailing beyond GMDSS Sea Area A2, to carry at least one AED suitable for marine conditions, with crew trained in its use and battery, pad and function checks built into planned maintenance[3]. Transport Malta frames it around the owner’s risk assessment: voyage length, passenger numbers, crew age and distance from emergency services[3].
The UK position is older and narrower. MGN 297 (M) asks passenger ship operators, particularly those regularly carrying more than 100 persons, to decide by risk assessment, and to consider an AED where one is likely to be used more than once in five years[4].
If you run open-registry tonnage
Check the flag’s current notices before relying on “optional”. Flag rules change by notice, not by convention, and the medicine chest requirements by flag state are where an AED requirement will appear first.
The US position: no carriage rule, a real liability rule
We found no general US Coast Guard regulation requiring commercial vessels to carry an AED. Federal first aid duties for fishing vessels, for example, sit in 46 CFR 28.210, which covers first aid equipment and training[11]. The wider picture by vessel type is in USCG first aid kit requirements by vessel class.
What does apply is the federal Cardiac Arrest Survival Act. Under 42 U.S.C. 238q, a person who uses or attempts to use an AED on a victim of a perceived medical emergency is immune from civil liability for resulting harm, subject to exceptions such as gross negligence[5].
The owner’s protection is conditional. The person who acquired the device is also immune, unless the harm came from failing to properly maintain and test it, or failing to train an employee who would reasonably be expected to use it[5]. State AED laws take precedence where a state provides its own immunity[5].
| Condition in 42 U.S.C. 238q | What it means aboard | Record to keep |
|---|---|---|
| Device properly maintained and tested[5] | Pads and battery in date, self-test passing | Monthly check log in the planned maintenance system |
| Expected users trained[5] | Officers who give medical care | Training certificates on file |
| Placement notified[5] | Notice to appropriate responders of where it is | Location in the muster list and the medical plan |
Why heart disease makes the case at sea
Illness, not accidents, is the leading killer of seafarers. The ILO global register counted 245 health-related deaths among 449 seafarer deaths reported for 2024[7]. In insurance data, Britannia P&I found 81% of crew fatalities were illness-related, and cardiovascular conditions caused 58% of those[6].
The heart also drives the emergencies that end voyages. Among 465 nautical officers surveyed in Hamburg, cardiovascular disease was 18.2% of the serious emergencies they had faced[8], and a 2023 review found suspected cardiovascular disease is the most common reason an evacuation is recommended[12]. The full picture is in what kills seafarers.
| Progetto Vita, Italy, 23 years[9] | AED volunteers | Standard EMS |
|---|---|---|
| Time to arrival | 5.7 minutes | 10.2 minutes |
| Shockable rhythm on arrival | 69.9% | 10.9% |
| Survival with good neurological outcome | 46.2% | 2.9% |
That is a shore program with 6,996 cardiac arrests, so treat it as direction, not a ship prediction[9]. The lesson for a vessel is the arrival time. Aboard, the only responder who can arrive in minutes is the crew, and Britannia notes that without an AED, survival from sudden cardiac arrest aboard is effectively zero[1].
Can a deck officer use one? The data says yes
Ship officers learn AEDs quickly. In a German study of 130 officers, 81.7% of the untrained group delivered an effective shock, and after a 7-hour course all 130 used the device correctly[2]. Time to the start of rhythm analysis fell from 72.4 to 60.4 seconds[2].
The ship environment is not the obstacle either. In an earlier test, all nine seafarers handled four AED models correctly, and every device recorded an ECG beside a running main engine[10].
Five decisions before you buy one
- Flag first. Confirm whether your flag requires or recommends a unit, and how many[3].
- Marine rating. Malta asks for a unit suitable for marine conditions[3]. Specify water and dust protection and operating temperature for your route.
- Location. Store it where the medical care officer and the bridge can reach it fast, and put the location on the muster list.
- Maintenance. Pads and batteries expire. Put checks in the planned maintenance system, which is also what keeps the owner’s federal liability protection intact[5].
- Training and telemedicine. Train every officer who gives medical care, and link the AED to your shore physician plan so the rhythm and events reach a doctor. See remote vessel medical planning and when to medevac a seafarer.
Discovery Health MD builds the AED into the chest review in our ship medical chest management service, and writes the cardiac section of the medical plan through maritime medical consulting. Crew training runs through our CPR, AED and first aid course. If scheduled cardiac drugs sit in the chest, see controlled substances management. Talk to a physician about your fleet.
Common questions
Are AEDs required on commercial vessels?
Not by international convention. Carrying an AED on a merchant ship is optional unless the flag administration requires it[1]. Germany requires them on seagoing merchant ships[2], and Malta’s Notice 198 calls for at least one on Malta-flag vessels[3]. Check your flag state first.
Does the US Coast Guard require an AED on board?
We found no general Coast Guard regulation requiring commercial vessels to carry one. Fishing vessel first aid duties sit in 46 CFR 28.210[11]. The federal law that applies to AEDs is 42 U.S.C. 238q, which governs liability for users and owners[5].
Is the crew protected from liability if they use an AED?
Under 42 U.S.C. 238q, a person who uses or attempts to use an AED in a perceived medical emergency is immune from civil liability, except for cases such as gross negligence or willful misconduct[5]. State AED laws apply where a state provides its own immunity[5].
What does the vessel owner have to do to be protected?
The acquirer’s immunity holds unless harm came from failing to properly maintain and test the device, failing to train an employee expected to use it, or failing to notify appropriate responders of its placement[5]. Keep maintenance logs and training records, and list the location in the medical plan.
Can untrained crew use an AED?
Often, yes. In a study of ship officers, 81.7% of untrained officers delivered an effective shock, and after 7 hours of training all 130 used the device correctly[2]. Training still matters, both for CPR quality and for the owner’s liability protection[5].
How much does an AED improve survival?
Time to the first shock decides it. In Italy’s Progetto Vita, AED volunteers reached patients in 5.7 minutes against 10.2 for EMS, and survival with good neurological outcome was 46.2% against 2.9%[9]. Britannia notes survival from sudden cardiac arrest aboard without an AED is effectively zero[1].
Why do seafarers need AEDs if most deaths are illness?
Because the leading illness is cardiac. Cardiovascular conditions caused 58% of illness-related crew deaths in Britannia’s claims data[6], and suspected cardiovascular disease is the most common reason an evacuation is recommended[12]. See medical emergencies at sea, by the numbers.
