What is the author's tone in the memoir, Castaway?

The tone of Lucy Irvine’s narration, not unlike that of her diary entries, conveys her youthful exuberance, literary sophistication, and dry British wit. Narrating her own memoir in the first person allows Irvine to establish her unique voice and breezy, conversational tone from the beginning, imprinting her personality on her narrative until its last word.