Here is a link to our trip to Palau at the end of February 09. Great shark action. Perhaps the best sharks though were on a snorkeling trip of nautilus beach. No mantas. Tiger sharks had been sighted and the divemaster thought that might have scared off the mantas which are usually around that time of year. Palau was very quiet, some days only one boat went out despite it being high season. One day of really bad weather, fine otherwise.
Photos posted at:
http://www.polisci.ohio-state.edu/faculty/lkeele/travel.html