You will see several whale sharks during your tour (between 4 and 10 is normal). Around noon it becomes harder to spot them. When it has been a while since the last encounter, the crew will ask the passengers if they want to keep looking for the sharks. It is not until passengers agree, that the crew will go back to the beach.
By the way, in Donsol it is only allowed to snorkel with the whale sharks; using diving equipment is forbidden.
♥ Visit Tagulandang Island ♥