I just e-mailed Corcovado Info Center last minute to see if they have they could help me with my visit to Corcovado Info Center. Kenneth, the owner, really went the extra mile and arranged the whole thing. Visit (and night) to Corcovado, snorkeling near the Island, kayaking over the river etc and stay at Drake Bay. I must admit the walked the extra mile for us.
Worth mentioning is the fast e-mail response (often within the minute)!