Animal skins  -  Brendan finds the new world by the advise of  Saint  Ita, the Abbess:
"You shall not find the land shown to you by the Lord in the skins of dead animals", St. Ita tells Brendan,
"because holy indeed is the land, in which human blood is not shed.  Get builders who know how to
make for you a vessel of wood.   Thus you shall explore, perhaps, that land."   (Vita Prima Sancti Brendani)