I want to write about some things that happened in the past – mostly so I don’t forget. In this case, I’m going to describe a particular cave dive that sticks in my mind. Now, there is a warning. This might not be exactly what happened – but it might also be true. It’s probably the way it happened. Let’s begin.
In case you aren’t familiar with cave diving, the main idea is to explore a cave that is completely underwater. You start outside the cave and you are already underwater. This is not spelunking – this is cave diving. We mostly went into springs in the panhandle of Florida – that was our roaming territory.
Just for fun, here is a picture of me with my cave diving gear.
Please don’t complain about the setup. This was a picture from my cave diving class. I learned quite a bit after this and changed things up – but still you can get an idea of what it was like. That was my friend’s van that we used to drive to different caves – it was pretty sweet.
Ok – now for this one particular dive. I am pretty sure this was at Twin Cave. Twin Cave is in the middle of Merritt’s Mill Pond in Marianna Florida. The only feasible way to get here is with a boat (unlike most cave diving in which you just walk into the water). It’s called “Twin Cave” because it has two entrances right next to each other (underwater). If you have a boat, you can use a tiny little wood platform connected to two trees to set up stuff.
My dive partner (Trey) and I hitched a ride with Pat Watson. He had a little john-boat and ferried us to the cave. He then went back and picked up two more divers – Pat was teaching them how to cave dive and this was one of their “check out dives”. Oh, I should add that at one point there was so much stuff in that little boat that it was barely above water. One tiny wave and I think the thing would sink.
Now for the dive plan. Go into Twin Caves and get into the lower levels. In this case, we would use diver propulsion vehicles (DPV) to get through the easy part and then proceed in the lower part by swimming. The DPVs are awesome (also called scooters). That’s the truth. I always wanted a scooter – but I never got one. Fortunately, my dive buddy had just recently upgraded his DPV for a bigger one. That meant that he still had his old one. BOOM – scooter time,
You’ve seen these scooters. They are basically small torpedo looking things (not exactly) with an electric motor. You connect a line from the scooter to you so that you can “drive” with one hand. That’s not really important, but I just wanted to say that.
Ok, so we start off on our dive. I seem to recall that it’s sort of tricky getting into Twin Cave. The main entrance is a vertical shaft – but then you have to turn horizontal right when you get in. If you don’t turn correctly, you hit the the bottom of the cave. Most cave bottoms have this silt stuff – if you hit it you change the cave water from pristine clear water to brown soup that you can’t see through. So – don’t hit the bottom (this will be important later. Oh, it’s even harder to get in this cave when you are trying to do with with a scooter. We probably had a stage bottle too.
I guess I should say something about stage bottles – for completeness. A stage bottle is an extra scuba tank that you mount on your side. You use this stage bottle for the first part of the dive – until it gets 2/3 full. At that point, you take the tank off and leave it on the line (there is a line running in the cave). You then proceed on the dive using the two tanks on your back. Using stage bottles lets you go much farther than just with double tanks.
Now back to the dive. The first part of the cave is pretty cool. It’s this big cylindrical cave that we called the subway. Ok, that might not be true. In my mind, we called it the subway. It was super easy to get through with a scooter – just imagine a long straight circular tunnel with a diameter of about 3 to 4 meters (let’s say 10 feet for imperials). Like I said, this is perfect for scooters.
At some point, we moved down to some small stuff and dropped off the scooters. There are two important points here. First, this part was deeper (can’t remember the exact depth) such that we will have more decompression time. Second, it was low and slow down here – longer time at depth also means more deco. I’m not going to really talk about deco time right now – but let’s just say that you don’t want to rack up a ton of deco time – it sort of sucks.
So we did our exploration of the lower part. Now it’s time to get the hell back to the entrance and do our deco. No more sight seeing – just hurry up. We pick up our stage bottles and our scooters and scoot out. Oh, quick note. There are two things that are awesome to see in a cave. The first is the warm glow of the Sun when you are near the cave entrance – this tells you that you are almost out. The second is your stage bottle. Picking up a stage just says “hey, you just got a bunch more air and a completely independent air supply – you have less chance of dying now”. It’s awesome.
Now for the whole point of this story. We are there on our scooters moving out of the cave while back in the subway. Ahead we see some lights. It was Pat and his two students. As we start to get near, something happens. The inflator on Pat’s buoyancy compensator (BC) just falls off for no apparent reason. In case you have never been diving, the BC is basically a bag of air that you can fill up or empty to adjust how you float in the water. It’s super important in cave diving because you want to stay off the bottom of the cave where all that silt is (remember I mentioned this before).
When Pat’s BC failed, so did his ability to stay off the bottom of the cave. It was weird – he just took a dive straight down. He sort of looked like a B-17 bomber that had just been shot out of the sky. I saw him try to make a correction to his buoyancy, but it wasn’t going to happen. He ended up just putting two fingers straight down to catch his fall (this is what we were taught so as to minimize the silt disturbance). It didn’t work. His crash produced silt. A lot of silt.
It was really amazing. This clear water subway tunnel suddenly turned into a tunnel with a wall. A wall of silt. You really can’t see much in this silt – it’s effectively zero visibility (but not as bad as clay in the water).
Since we were traveling along at a good pace with the scooters – it only made sense to slow down quite a bit. I knew there were three divers inside that wall of silt, but I didn’t know WHERE exactly they were. So I slowed down. Gradually clicking the throttle trigger on the scooter to maintain a slow crawl speed.
To my surprise, my dive buddy chose a different strategy – he decided to just keep going at his current speed. I saw him head straight into that wall of silt – waiting for some type of collision. But no, he made it though. It was a bold move and it paid off.
For me, I went through slowly and made it to the other side of the silt wall (which wasn’t very thick). After that we did our deco and finished the dive. I sort of recall not taking the boat back to the van and staging area. Instead, we used the scooters the rest of the way. It didn’t matter at that point – you don’t have to worry about saving scooter battery or scuba air.