This historical sociolinguistic study investigates the language of English seamen in the seventeenth century. Built on language data compiled from log books (Matthews 1935) and a survey of the maritime population from 1582, the author argues that the seafaring community had developed its own sociolect, which was based on the dialects of Southern England. Writers (e.g. Jonathan Swift, Daniel Defoe) and historians describe this “Ship English”: [S]ailors stood out from landsmen in a variety of ways. In the first place by their dress [...] Sailors were also recognisable by their speech, in which technical terms, slang and oaths had thickened to produce a private language. (Burke 1996:44-45) Following Ross and Bailey (1988), the author argues that this sociolect emerged from dialect contact (Trudgill 2004) aboard ship, with Southern dialects as the major input varieties: Several phonological features of Southern Early Modern English (e.g. diphthongization of Middle English /u:/ and /a:/, split of /u/ into /ʌ/ and /ʊ/, /w/-/v/ interchange) are pervasive in the data. Apart from being a interesting case study in itself, the results might be of importance for research on pidgins and creoles and colonial dialects: it has been argued (Hancock 1976) that nautical English has had a profound impact on the emergence of anglophone creoles because it – rather than some kind of Standard English – was the actual “superstrate” variety for most creoles. For the same reason, it might have influenced the emergence of the overseas varieties of English. / text