The fledgling community was forced to adapt to the needs of the Bounty crewmen knowing very little Tahitian and the Tahitians very little English. The resulting Creole became Pitcairnese.
It is important, however, to note that the English-speaking crewmen did not all speak the same dialect of English. Geographically, the mutineers were drawn from as far as the West Indies, with one mutineer being described as speaking a forerunner of a Caribbeanpatois language. Additionally, Fletcher Christian at least was a well-educated man, which at the time was a major difference in speech.
As mentioned above, Norfuk is descended predominantly from the Pitkern (Pitcairnese or Pi'kern) spoken by settlers from the Pitcairn Islands.
The relative ease of travel from English-speaking countries such as Australia and New Zealand to Norfolk Island, particularly when compared with that of travel to the Pitcairn Islands, has meant that Norfuk has been exposed to much greater contact with English than Pitcairnese has.
The difficulties in accessing the Pitcairn population have meant that a serious comparison of the two languages for mutual intelligibility has been largely impossible.