Tourists who want to go snorkeling in Manokwari bay need to avoid standing on the reef. It takes tens of years for corals to develop their "skeleton" to a size similar to a human head. Experienced snorkelers usually choose their snorkeling spots along the edge or wall of the reefs when the tide is low. Beginning snorkelers have to do the same thing too. However, for safety reason they can wear life-jacket to prevent them from drowning or drifting away pushed by the sea current.
Also read: Snorkeling in Mansinam island