There are several real-live caves, both fresh and salt water, here on the Big Island.
(as opposed to caverns, which there are many, many of as well)
One of the better-known is 3 Room Cave, visited by several local dive charter
operators on their "advanced" dives. I am
REALLY uncomfortable with
the notion of taking most recreational divers into that cave (especially the back
room)... but some operators do it. To me there are better (safer) cavern dives
in the same general area, which, from a liability standpoint would seem to make
more sense. But I'm tilting at windmills here.
You'll
never find the fresh water cave at South Point without a local guide -
it's 30 miles from
anywhere.
Tom Winters:
[...]. I followed the movement to the head of THE biggest moray eel I have ever seen - and they just are not supposed to get that big. Forget asking the length - no one believes me anyway. Never saw it again.
Good bet that it was
Gymnothorax Javanicus, the Javanese Moray. They get
large enough to be your regulation sea monster
AKA the BFE