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Regulatory explainer2026-07-17 · 5 min read

TMAS, Radio Medical and Private Telemedicine — What's the Difference?

What a Telemedical Assistance Service (TMAS) is, how radio medical advice began, and where private maritime telemedicine fits alongside it.

What is a Telemedical Assistance Service (TMAS)?

A Telemedical Assistance Service (TMAS) is a state-designated medical service that provides ships at sea with medical advice by radio or satellite communication, 24 hours a day, free of charge. Under the Maritime Labour Convention, 2006 (MLC 2006), every ratifying state must ensure that such advice is available to all ships, irrespective of the flag they fly.

The legal basis sits in MLC 2006 Regulation 4.1 and Standard A4.1, paragraph 4(d): the competent authority must ensure, by a prearranged system, that medical advice by radio or satellite communication — including specialist advice — is available around the clock, and that this advice, including the onward transmission of medical messages, is free of charge to all ships. The requirement builds on earlier instruments, notably ILO Convention 164 on health protection and medical care for seafarers.

The wider framework is described in IMO circular MSC/Circ.960 (Medical Assistance at Sea), which places TMAS as one of five elements in an optimal arrangement — alongside rescue coordination centres, means of intervention at sea, shore-based facilities and common operating procedures. Designated radio-medical stations are also published in the ITU List of Coast Stations and Special Service Stations (List IV), and radio traffic exchanging medical advice with listed stations has historically been exempt from charges under the ITU Radio Regulations.

What is radio medical advice, and where did it come from?

"Radio medical" is the original name for the same function: a doctor ashore advising a ship's crew over radio. The first licensed radio medical service began in 1920, when the Seamen's Church Institute in New York received a licence for its KDKF radio station to answer medical calls from ships.

National services followed quickly — Sweden opened its radio medical centre in 1922, the Netherlands in 1930 and Germany in 1931 — and in 1935 Italy's Centro Internazionale Radio Medico (CIRM) in Rome extended the model internationally, offering free radio medical assistance to ships of any nationality. Today the terms Radio Medical, Medico and TMAS all describe descendants of this service, formalised under the MLC and IMO frameworks.

Who provides TMAS in Sweden?

Sweden's TMAS is arranged by the Swedish Maritime Administration (Sjöfartsverket) and coordinated through the Joint Rescue Coordination Centre (JRCC) in Gothenburg, which acts as the point of contact between vessels and shore within the Swedish search and rescue region.

The clinical side was provided for a century by doctors at Sahlgrenska University Hospital in Gothenburg — a service dating back to 1922. Since 6 November 2024, the Swedish Maritime Administration has contracted the digital healthcare provider Kry to supply the physicians, with doctors available around the clock via radio, satellite, telephone or email. The service handles on the order of a few hundred consultations a year.

What does TMAS cover — and what sits outside its remit?

TMAS is designed for the acute case. Its core duties, reflected in the IAMSAR manual and MSC/Circ.960, are to be reachable 24/7, make a prompt remote assessment, advise the ship's master on treatment with the means available on board, provide specialist input when needed, and recommend evacuation where justified — in coordination with the rescue services. On those terms it performs well, and it is free.

What a statutory TMAS is generally not built for is everything around the acute call. The duty doctor typically has no prior knowledge of the crew, their medical histories or the vessel's medical stores beyond what is described during the consultation. Continuity between calls is not guaranteed, since cases are handled by whoever is on duty. And the documentation produced serves the medical consultation itself — it is not, as a rule, designed to feed an employer's HSE system, incident statistics, fitness-for-duty follow-up or return-to-work planning. None of this is a criticism; it is simply outside the mandate the convention gives the service.

How does private maritime telemedicine differ?

Private telemedical providers are contracted by the shipowner, operator or duty holder rather than mandated by the state, and they are structured around the employer's obligations as much as the individual case. That typically means advance knowledge of the crew and the medical equipment on board, continuity across a case, written case documentation for the company, integration with emergency response plans, and advisory support on prevention, medical stores and training.

A private service is a complement to TMAS, not a replacement. The statutory service remains available to every vessel free of charge, and in an evacuation the TMAS–rescue-coordination chain remains central. The practical differences are easiest to see side by side:

DimensionTMAS (statutory)Private telemedical advisory
MandateRequired by MLC 2006 Standard A4.1; arranged by the stateCommercial contract with the shipowner, operator or duty holder
Cost to the vesselFree of charge to all ships, irrespective of flagPaid service under contract
Who it servesShips at sea and their seafarersWhoever the contract defines — crews, offshore technicians, sites
Clinical scopeAcute assessment and advice to the master; evacuation recommendationsAcute advice plus follow-up, prevention and medical-preparedness support
Prior knowledge of crew and vesselGenerally none; each case assessed from scratchCan include crew context, on-board equipment and site procedures
ContinuityDuty-doctor model; may vary between callsCase ownership and follow-up can be contracted
DocumentationRecord of the medical consultationEmployer-facing case documentation and reporting, within medical confidentiality
Offshore wind personnelDepends on whether the person is a seafarer on a shipCoverage defined by contract, regardless of seafarer status
SAR coordinationDirectly integrated with JRCC/MRCCAdvises within the employer's emergency response plan; the statutory chain still applies in an evacuation

Who covers an offshore wind technician standing on a turbine?

It depends — and this is where the offshore wind sector should look closely. The MLC's guarantees attach to seafarers, defined as persons working "in any capacity on board a ship to which this Convention applies". A wind turbine is not a ship, and a technician working on a transition piece or inside a nacelle is, at that moment, not on board one.

Even aboard crew transfer vessels the picture varies. Flag states interpret the seafarer definition differently, and several — the UK among them, in guidance such as MGN 471 — have indicated that specialist offshore technicians whose principal place of work is ashore may fall outside it. Whether TMAS-style protections apply therefore depends on the flag state, the asset type and how the work is organised. In practice, wind farm duty holders bridge this gap through their own arrangements: emergency response plans, contracted medical support and telemedical services specified in project contracts rather than assumed from maritime law.

Written by Elia Malmsten, Clinical Lead at Alvyri Crew — Swedish-licensed physician, specialist trainee (ST) in anaesthesiology.

Frequently asked

Is TMAS free of charge?
Yes. MLC 2006 Standard A4.1 requires that medical advice by radio or satellite communication, including the onward transmission of medical messages, is available free of charge to all ships at sea, irrespective of flag. The cost is carried by the state that arranges the service.
Who runs TMAS in Sweden?
The Swedish Maritime Administration (Sjöfartsverket) arranges the service and coordinates it through the Joint Rescue Coordination Centre in Gothenburg. Physician cover was provided by Sahlgrenska University Hospital for around a century; since November 2024 the doctors have been supplied by the digital healthcare provider Kry.
Does TMAS cover offshore wind technicians?
Not automatically. TMAS obligations attach to ships and seafarers. A technician on a turbine is not on board a ship, and even on a crew transfer vessel their status as a seafarer varies with flag-state interpretation. Coverage for wind farm personnel is therefore usually established contractually, through the project's emergency response and medical support arrangements.
If we contract a private telemedical provider, should crews still call TMAS?
The statutory TMAS remains available to every vessel and is directly integrated with search and rescue coordination — in an evacuation decision, that chain matters. A private provider complements it with continuity, documentation and employer-facing support; a well-drafted emergency response plan defines when each is contacted.

Questions about your coverage? Talk to the team.

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