Hoyarsabal's "Les Voyages Avantureux"
That Basque was still the predominant European language normally spoken on the West Coast of Newfoundland in 1677 is unquestionably obvious or Detcheverry would not have published his sailing directions in Basque. He was certainly capable of speaking French or he would not have been able to translate Hoyarsabal's "Les Voyages Avantureux" into Basque.

The 1579 original of "Les Voyages Avantureux".

Piarres Detcheverry's translation of "Les Voyages Avantureux", plus the 'advances' around the Gulf.