The SMALLEST Cave! We reached our limit!

Coming up, Jonathan and Todd explore a new section of Jackson Blue Spring off the main line. What will they find? Welcome to Jonathan Bird's Blue World! Jackson Blue Spring is one of the most powerful springs in Florida, pumping out more than 60 million gallons of water every day. It flows from the spring into Merritt's Mill Pond, a man-made reservoir created by damming up the river originating at the spring. Cameraman Todd and I first dove Jackson Blue Spring with Ed Sorensen, one of the most experienced cave divers in the world. Of course, in one dive, we saw very little of this cave, which has miles of interconnecting passages extending more than 5,000 feet from the entrance. So today, we've come back to do a little exploring on our own. Merritt's Mill Pond lies in Mariana, not far from Tallahassee on Florida's Panhandle, a cave diver's paradise. Todd and I rented a boat from Cave Adventurers, so we can cruise around the pond diving in all the caves. And today, we're heading to the biggest cave on the pond, Jackson Blue Spring. You know, giving me a boat is a very bad idea. I'm a highly experienced boat driver. How hard can it be? It's pretty clear water if you ask me. Clearest pond I've ever seen. Look at this water. It's crystal, crystal clear. So what are we doing? Once we're all suited up and we've checked each other's gear, it's time to go cave diving. But first, we have to swim across the shallow eelgrass bed thriving just outside the spring entrance. As we approach the cave entrance, we can feel the flow of water getting stronger. 60 million gallons a day come out of this big hole, so swimming into that strong flow is like swimming up a swift river. I lead the way in. Then I can turn around and get a shot of Todd coming in behind me. Once inside the cavern zone, we adjust our buoyancy and then push through a smaller section where the flow gets really strong. The water is so clear that you can't tell how fast it's moving. There are no suspended particles speeding by, just the quiet, unrelenting power of moving water. Once through the narrow entrance, we are still swimming upstream but the force of the flow is a little less. Cave divers generally use a frog kick to minimize disturbing the bottom. But this kick is not as powerful as a normal flutter kick, so we progress slowly. Still in the cavern zone with light from the entrance visible, there's a great little restriction that's excellent practice. I go first. This isn't a particularly tight restriction for a side mount diver, but a back mount diver would not fit. I pop out on the other side, still in the main cavern, and then Todd has a turn. For us, the trickiest part of these things is getting the camera through unscathed. Soon we reach the stop sign at the end of the cavern zone. Past this sign we can no longer see daylight from the entrance and we have entered the exclusive realm of cave divers. This sign is a reminder that only properly trained and equipped divers should be cave diving. As we continue past the stop sign, we reach a crack called the chimney, where the cave goes quite a bit deeper. It's not actually vertical, but still pretty steep, and the strong water flow up out of this section seems to be telling us to stay out. But it's the way into the cave, so down we go, following the main line. At the bottom of the chimney, we reach a low section. I have to fight my way through. Then it opens up into a much larger, wider section, and thankfully the flow is weaker. It's not far until we reach a pair of line arrows. Of course they always point the way out, but when there are two, it means there is a side passage nearby. Todd and I are going to do what is called a jump, to a side passage called Parallel Line. In order to keep people from being confused, lines into side passages do not usually connect directly to the main line. So I use one of my spools to temporarily connect them. I tie into the main line and swim only about 20 feet to the line going into the side passage. This may not seem necessary, since we can actually see the main line from the end of the side passage line. But we have to always plan for the possibility of not being able to see anything in case of a silt-out. This way, we have a line we can follow by feel, all the way out of the cave if we had to. Now following the line in the side passage, we are exploring a section of cave we have never seen before, so this is really exciting. There's still plenty of water flowing in the side passage, but now we are going with the flow, because this is a downstream passage. The passageway goes up and down like a roller coaster, so we can't see what's around each hill or valley. It's fun. In the depressions on the bottom, some areas have accumulated bits of fossils. There are pieces of coral, sea urchins and other calcium-heavy bits that date back millions of years, to a time when this limestone was part of the seafloor. Soon we reach a very small restriction that we want to try to get through. But it looks awfully small. Todd gives it a whirl. I think that if Ed was here to give us guidance, we would make it through, but without expert assistance, we both chicken out. So that means we are at the end of the line and it's time to turn around. To get back to the main line, we must swim against the flow again. As we come back to the entrance of the side tunnel, alas visibility is still excellent and we can see my jump line clearly. Swooling up the jump line is kind of difficult while holding a camera, which is why we usually have a three-person team, so there's always someone with both hands available for this kind of thing. But placing my camera on the bottom works pretty well, almost like a lantern, for the short-distance spool up. With my spool stowed, we can now start heading back out on the main line. And of course, now we're going with the flow, so it's easy. Going up the chimney is a little tricky, because the water tends to shoot you up there faster than is safe, so we have to hold on a bit and slow down. Then of course, protect the camera lenses. Ooh, that was a close one. At the top of the chimney, there's a huge air bubble on the ceiling, an accumulation of all our exhaled breaths. And whenever I see a really big air bubble, I always wonder the same thing. Can I stick my head up in there? And the answer is yes. So, I grab Todd's GoPro. There are so many reasons why you don't want to actually breathe this air. Not the least of which being that it's our exhaled breath. Ew. With that silliness over with, we start making our way back towards the entrance. It's not long before we're back in the cavern zone and we can see the light of day. And while getting in through that narrow passage was hard work, going out is like being shot out of a cannon. When I reach the other side, I have to grab a rock to keep from being shot completely out of the cave and missing my safety stop. Todd follows behind and we find a corner out of the main water flow to do a short stop. Todd's computer indicates that we have no decompression obligation, just a 3 minute safety stop. Jackson Blue Spring is a huge cave system, which would take years to fully explore. Furthermore, we have reached the limit of what we can see on Open Circuit Scuba with its extremely limited dive time. If we're going to see more of this amazing cave system, we're going to need rebreathers like Ed has. So it's possible that a new piece of gear will be coming to the Blue World. Stay tuned! Hey you guys! Check out that video! It's a really good one! Also, this one is pretty good too! Oh, and don't forget to subscribe!