I have dove in Vortex Springs before, quite a few times and even at night. Beautiful place and fun to dive. Even non-divers enjoy swimming/playing in the water that flows from the cave down to the creek/
As for the possibility that he was "sucked into" another underwater stream inside the cave, I'm not even sure how that could be possible. Vortex Spring produces 28 million gallons of crystal clear freshwater a day. That water flows OUT of the cave. It filters thru the limestone and passages that make the cave, out of the cave at the rate of millions of gallons a day at a constant rate of flow.
For instance, I dove another spring a few miles from Vortex. It had a tiny cavern with a small opening. I actually had to fight my way into it against the flow of water that was coming out. I had to grab onto the rocks and pull myself into it until I got into the "room" of the cavern. Leaving the cavern was a blast as the water pressure just shoots you out of the cave. I even went back in just for the fun of being shot out of it by the water.
This is such a mystery. I have no clue why anyone would risk cave diving alone. There is too much to go wrong. Some passages require you to remove your tanks and gear and squeeze thru passages and then bring your gear thru and put it back on. My husband and I were cavern/cave diving once and it was a passage that went straight down, you swam around around a huge rock at maybe 90 ft and then came up again. I had trouble with my ears (blockage/pain/due to the cold water) and i stayed at about 35 feet while he went down to see it. ( This was our honeymoon and he would likely not get the chance to dive it again as it was a huge distance from our home.)
I waited at 35 feet from him and it was taking a long time. Turn out his mask came off at the bottom and he was blindly trying to find it, searching with his hands, feeling around. Thank God he found it, cleared it of water and returned to me. OMG, He could have died, I could have became a widow on my honeymoon.
This case puzzles me so much. It haunts me as my ex husband is still an avid diver. He braves the gulf of mexico to go "rig diving" which is spearfishing deep in the gulf . It a very challenging dive where many of the fish are bigger than you and one mistake can kill you. They shoot the fish with a speargun and then have to fight the fish to bring it up. The spear is tied to a line that the diver holds. A few foolish divers have attached that line to their bodies, speared a fish that was bigger than them and were last seen heading down at the mercy of the fish into the bottomless gulf. Their bodies where never recovered. Even though he is my ex-husband, I would be devastated to lose him and honestly wish he would stop doing that type of diving. It scares the hell out of me.
But diving is a beautiful thing and there are many fairly safe ways to dive. The weightless of floating along, being able to do flips, to float along upside down and a million other things makes it so delightful.
This link has awesome pics and videos inside the cave. i would recommend to check it out. It has 35 great pics and 7 videos. One amusing pic shows a vienna sausage can. The eels like to eat vienna sausage and you can feed them that. I have also hear of divers bring cans of "squeeze cheese" (in a can like whipped cream) to feed fish underwater.
http://www.lovethesepics.com/2012/06/adrenaline-junkies-cave-diving-vortex-spring-37-pics-5-videos/
Ben, where are you? Will we ever know?