Almost every caves, strong creatures can't follow with you. Even some caves need to go underwater to get useful resorces or trophy and dossier and again, most creatures that you are familiar usually are not good at diving and swiming. If they are good at diving and swiming, they are too weak to travel caves and underwater's creatures.
But after baryonyx released, no worries. It will keep your safe and help combat from almost every normal cave's creatures(high lvl megalosaurus will tough at night times, but it is weak at day times and still your bary can tanking few sec if you spend points on health for most.), even it can dive into the water endlessly if you have preparation about oxygen, coldness or scuba and still it will help help your combat from underwater's creatures.
I would argue that this dinosaur is the strongest mount that can fight on both land and in the water. I had one that was bred multiple generations, full imprint, purple saddle. I named him Fury to represent all of the anguish I experienced leading up to his creation. He was able to handle anything I threw at him with ease. People were surprised to hear that I was easily able to kill both squids and alpha carnos with him. Never got to attempt an alpha Rex. He met his match when I attempted an alpha squid. RIP Fury.