In 'Aquaman: Throne of Atlantis', Aquaman summons a Megalodon shark which quickly rises out of the water and swallows his enemy, Black Manta, alive. ( http://i.imgur.com/nGocDro.gif )

Here, we see Black Manta inside the shark's stomach. His suit will protect him and he has plenty of air, but there's only one way out and it's not back out the mouth. He'll have to wait and travel through the shark's digestive system.