translate English to French: 5hr30m. I would recommend the latter, as the NGV is not much fun on rougher crossings (you cannot go above deck) and the crew of the slower boat are hilarious--loud, friendly and warm, though they don't speak much English or French!
Liaisons aériennes quotidiennes avec Nice et Marseille assurées par CCM-Airlines (Compagnie Corse Mediterranée).