This is apparently NOT Thunderball Cave. It was NOT used in a James Bond movie starring Sean Connery. It is most definitely Ariel's grotto, just ask Emma.
You go in at slack tide or close to it, otherwise there's quite a current that runs through the cave. You see this little sign and you look all around trying to figure out how to get in. It's one of those cool things where you just keep swimming toward the sign until you see the way in. At high tide, you have to swim underwater to get through the openings, at low tide, you don't have to swim down to get in, it's still a little tight but it's easily doable. Once you're inside, it opens up really high. There are small holes in the cave where you can go in and out in several different places, some are tighter squeezes than other places. This is when it's REALLY nice to have flippers. That added strength is really nice. I could have spent hours in here, the fish were amazing, all sorts. there was some incredible coral formations both inside and outside the cave. There were several nurse sharks hanging out outside the cave.
Jack was NOT persuaded to come swimming, he and Gramma sat in the dinghy with our clear bottomed bucket looking at fish. Apparently that was a lot of fun too. And don't worry about Gramma, when Granddad was done, she got her turn too. Emma was NOT sure about going in, but once her dad was inside, she followed.
This looks a little scarier and lower than it actually was.
This is where you come into the cave.
Emma was NOT persuaded to wear a mask, even for a minute but she played with all of her imaginary friends and had a blast. It's SO nice to not worry about towels, it's so warm outside, that being wet doesn't matter. Awesome.