Bones are barriers that appear in Hungry Shark World. They are the weakest barrier in the game, since they can be broken by every shark except for the Blacktip Reef. They make a cracking noise when destroyed. They usually block long areas that wouldn't be accessible unless you break the barrier.
You will need to boost in order to break Bones.
In the Pacific Islands, they appear near underwater currents on the east area on the right side from the spawn point.