Liber Fidelium Crucis
In it, Marino relays a story about Prester John almost identical to that of Simon of St. Quentin.
As for the rest of the book, Sanudo adeptly discusses 13th-century Mediterranean history, especially those episodes that feature Louis IX of France and Charles of Anjou, king of Naples. The first two books outline the rationale of and logistics for his crusading plan, whereas the third book offers a history of the Crusades up the point of composition. Sanudo draws on other Prester John writers, including Jacques de Vitry, to supplement Sanudo's first-hand accounts.
Read the full text in a recent translated edition.
