World's Largest Sea Cave?

This is a view from inside Hui Hui Cave, said to be the largest sea cave in the world. It's a huge, almost-spherical bubble, left over from the volcanic caldera that gave rise to the Poor Knights Islands 10 million years ago. Painted Cave in the California Channel Islands is also said to be the largest sea cave in the world. Having visited both, I am certain that both are exactly the same size.