What is "seaspeak"

Seaspeak is a controlled natural language (CNL) based on English, designed to facilitate communication between ships whose captains' native tongues differ. It has now been formalised as Standard Marine Communication Phrases (SMCP).

While generally based on the English language, seaspeak has a very small vocabulary, and will incorporate foreign words where English does not have a suitable word.

There are other similar special-purpose CNLs, including aviation English for aircraft, and the English–French hybrid PoliceSpeak for safety administration of the Channel Tunnel.