Just an anon observation, but noted this aerial image of Epstein Island from the latest articles of the potential big name drop shortly, and the submarine thing came back to mind…
It's pretty clear there is very shallow and clearly visible waters around almost the entire island. Except, where the temple is.
Deep water only presides at that point of the island which could have easily concealed a small below water sub landing dock into the hill beneath the temple, and may have been key to its location.
This could also indicate key likely sub routes that may have been taken.