Went kayaking on a local river and decided to stop at some freshwater springs and go swimming. The area has a lot of underwater caverns; basically tunnels where you can dive down, swim in one end and pop out another. Went down a couple of times, explored and decided to swim through one. Wrong move. They are a lot longer than one would think plus once you go in one you seem to lose your sense of direction. I was able to get to the other end and pop up to the surface but it was close. Only equipment I had was a mask.
Anyone do serious underwater cave diving?