"Underwater caves" refers to caves or hollow areas that are located beneath the surface of water, such as rivers, lakes or the ocean. These caves are formed over time by natural processes, and they can vary in size and complexity. Full definition
There are a few underwater caves in the area too. (mauikai.com)
The park is home to one of the longest known underwater cave systems in the world. (bahamas-guide.net)
An underwater stage has been added, which in turn means... Diving equipment will be in the game so you can explore underwater caves. (thatvideogameblog.com)