I used to scuba dive (PADI certified). Have seen some incredible things under the water.
That said, you could not pay me enough to cave dive. Diving itself is dangerous enough even if you are trained. I have seen certified divers make mistakes that almost got them killed. Also once had an equipment (regulator) failure at 110 feet. Scary, but had a backup (octopus) and simply went to the surface while taking proper safety stops. You cannot do that if your are in a cave.
Cave diving is exponentially more dangerous. As the sign in the article says, there’s nothing worth seeing in a cave that’s worth dying for.
I took a SCUBA class in college, as a PE class. My instructor was going to lead a group to Cancun for diving that Spring and I was excited at the thought. I simply could’nt bring myself to allow the apparatus to breathe for me, so I had to drop out of the class. A week or so after that Spring break, I saw a former classmate who had gone on the dive. The instructor was lost.....they searched for hours after she didn’t turn up on schedule and went back to the area the next day to search some more. They could only conclude that she had developed nitrogen narcosis and just swam off. She was extremely overweight (so perhaps should have floated to the surface if she had been attacked by something), but was also extremely experienced. No sign of her ever again.
Ginnie springs is really cool and a relatively safe place to experience scuba diving in a fresh water spring.
http://ginniespringsoutdoors.com/dive.php#Ginnie Spring
The article said they found them in ~260 ft of water. Assuming they dove to that depth and weren’t carried down by currents, that’s quite deep for scuba equipment, isn’t it?
Did a few long lava tubes in Hawaii, including one with a very tight passage. Having done them, had enough of that.