SEASPEAK, also English for maritime communications. The English of merchant shipping, a RESTRICTED LANGUAGE adopted in 1988 by the International Maritime Organization (IMO) of the United Nations for use in ship-to-ship and ship-to-shore communications as a necessary consequence of vastly increased shipping during the 1960s–70s. The need for regularization of practices in one language and the training of officers in its use was agreed, and English, already the language of civil aviation, was chosen by the IMO.

In 1982–3, Seaspeak was created by specialists in maritime communications and applied linguistics, working in Plymouth and Cambridge and funded by the UK government and Pergamon Press. It was made as concise and unambiguous as possible, was restricted to no more than two propositions in any message, allowed for constant checkback and confirmation, and made as few changes as possible to existing practice. The SEASPEAK Reference Manual by Weeks, Glover, Strevens, and Johnson (Oxford: Pergamon, 1984) was published after worldwide sea trials. Apart from special-format messages (as in stereotyped weather forecasts), all messages begin with a message marker that indicates the nature of what follows, such as advice, information, instruction, intention, question, request, warning, or a response to one of these. Below is a typical exchange, in which a ship called Sun Dragon calls up Land's End Coastguard in England, to inform them of a change of plan:Ship. Land's End Coastguard, Land's End Coastguard. This is Sun Dragon, Sun Dragon. Over.Coastguard. Sun Dragon. This is Land's End Coastguard. Switch to VHF channel one-one. Over.Ship. Land's End Coastguard. This is Sun Dragon. Agree VHF channel one-one. Over.Coastguard. Sun Dragon. This is Land's End Coastguard on channel one-one. Over.Ship. Land's End Coastguard. This is Sun Dragon. Information: I am returning to Mount's Bay. Reason: north-west gale and very heavy seas. Over.Coastguard. Sun Dragon. This is Land's End Coastguard. Information received: you are returning to Mount's Bay. Reason: north-west gale and very heavy seas. Question: do you require assistance? Over.Ship. Land's End Coastguard. This is Sun Dragon. Answer: no assistance required, thank you. Nothing more. Over.Coastguard. Sun Dragon. This is Land's End Coastguard. Nothing more. Out.

Compare AIRSPEAK. See ESP, -SPEAK.