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HMRC internal manual

National Minimum Wage Manual

HM Revenue & Customs
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Specific occupations & special groups: mariners and seafarers

Relevant legislation

The legislation that applies to this page is as follows:

  • National Minimum Wage Act 1998, sections 1 & 40 and National Minimum Wage (Offshore Employment) Order 1999 (SI1128)

Working or ordinarily working

Under section 1 of the National Minimum Wage Act 1998, a worker is entitled to be paid at least the national minimum wage when they are working, or ordinarily working, in the United Kingdom (NMWM05030).

A seafarer who can establish a sufficient link to the United Kingdom can be regarded as “ordinarily working” in the United Kingdom and able to bring a claim in respect of national minimum wage through a tribunal, regardless of the nationality of the seafarer or the flag of the ship on which they are employed.

In order to determine whether a seafarer “ordinarily works” in the United Kingdom a NMW Officer will consider which country the seafarer’s employment base is in, taking into account of

  • where the seafarer’s tour of duty begins and ends; and
  • where the seafarer is subject to income tax and National Insurance contributions.

Internal waters

All mariners or seafarers working on ships within United Kingdom internal waters are entitled to be paid at least the national minimum wage. This is regardless of where the ship is registered or whether the worker ordinarily resides in the United Kingdom.

Care should be taken to avoid confusing the term “internal waters” with “territorial waters”.

  • The term internal waters is not specifically defined in national minimum wage legislation but it has been accepted to mean that it covers all water and waterways on the landward side of the baseline from which the UK territorial waters is defined. It includes waterways such as rivers and canals, and sometimes the water within small bays.
  • Territorial waters as defined by the 1982 United Nations Convention of the Law of the Seas (UNCLOS), is the belt of coastal waters extending at most twelve nautical miles from the baseline (usually the mean low-water mark) of a coastal state.

Section 40

Under section 40 of the National Minimum Wage Act 1998, workers who are ordinarily United Kingdom residents and who are working on ships registered in the United Kingdom, are entitled to be paid at least the national minimum wage wherever the ship is, provided at least some of their employment takes place in the United Kingdom or its internal waters.


The following table summarises when mariners and seafarers are entitled to national minimum wage:


MARINERS AND SEAFARERS Internal waters External waters External waters Comment
      UK registered ship Non UK registered ship  
  Worker “ordinarily working” in the UK        
  Worker not “ordinarily working” in the UK YES# NO NO #Although not “ordinarily working” in the UK, the worker is entitled to be paid at least NMW for the time working in the UK and internal waters.
  Ordinarily UK resident - some employment in UK/internal waters
  #Section 40 applies in this scenario, see above.        
  Ordinarily UK resident - all employment outside UK/ internal waters Not applicable NO NO  

Workers included as mariners and seafarers

Mariners and seafarers include workers:

  • engaged on ships in the course of navigation. “Navigation” means ordered movement across the water. To be a ship, a vessel does not need to have a rudder or its own motive power.
  • engaged in fishing or dredging [unless the dredger is excavating the sea bed or its subsoil in the course of pipe laying (NMWM06200)].
  • on semi submersibles and similar vessels being used as ships (often in the oil and gas industry). This use based approach was followed by the Court of Appeal in Perks v Clark (2001) which held that a semi-submersible drilling rig could be considered as a ship. If the vessel is not regarded as a ship, workers on board may be offshore workers (NMWM06200).

There is specific legislation relating to the entitlement of offshore workers (NMWM06200) and share fishermen (NMWM06230) for national minimum wage purposes.