Diving Antarctica 2019: Drysuit Diving at Bonne Terre Mines

My new OMS San Diego dry suit and my new Aqualung Glacia cold water regulator are about to make their debut, just in time for my weekend trip to the Bonne Terre Mines. Prior to leaving, I tested out all of my new equipment in the pool at Lynnhaven Dive Shop in Virginia Beach, VA. Still in shock that I own this new investment for my impulse trip to Antarctica; I spent about an hour in the pool with no issues and getting to know my equipment. Spending this time in the pool increased my excitement to jump on a plane to Missouri.

About three weeks ago I stumbled upon a dive shop located in Northern Virginia. On their website they offered a trip to the Bonne Terre Mines. This was huge for me to get a few more dry suit dives, five more to be exact. I anxiously dialed up the dive shop waiting to talk to someone about squeezing in a spot for me as full payment was due in July and it was now mid August. Let’s just say within the hour, the dive trip was booked, my plane ticket and rental car were all set. Impulse trip to Antarctica why not an impulse trip to Bonne Terre. I could not pass up an opportunity to get more experience in a different location. More cold water training, which is exactly what I need to prepare for Antarctica.

Below the town, Bonne Terre Mine is a quarter-mile underground. Your first steps underground are musty and wet with slanted walk ways and 68 steps. Each diver is responsible for carrying their own equipment down to the dive platform underground. The dive platform and the dives offered are completely unaffected by the weather above.  The air temperature remains at 62 degrees while the water temperature stays at a constant 58 degrees year round with no thermocline. Thermocline means the water temperature changes as you go deeper underwater, usually the water gets colder.  However, that is not the case here, the water will stay 58 degrees at the surface or 90 feet deep. With that said do not underestimate the 58 degrees while you are preparing for your dives.

Bonne Terre is known as the Billion Gallon Lake with miles of dive trails to swim through.

As a first time diver at Bonne Terre, I dived trails 1 through 5. All new divers to Bonne Terre are required to dive the first five trails. This is a great way to get acclimated to mine diving and not miss anything Bonne Terre has to offer. Another unique aspect of the Billion Gallon Lake is the constant 100 foot visibility with no natural light. There are some part of the dive that are dark, almost like night diving. As you dive you can see far above the surface of the water and deep below you, it is quite incredible.

The pillars you see in the above picture are man made, as big as sequoia trees.  It is very hard to describe how massive and beautiful these pillars are especially while diving. Underwater at 30 feet deep you can look up see the same pillars reaching the ceiling above the dive platform. They are as wide as houses and as tall as sky scrapers. Just beautiful.

Dives are only conducted on Saturdays and Sundays and as mentioned before you are required to dive the trails in order. Trails 1 through 5, then 6 through 10 and so on. A big thing to note is that there are no refunds given for any reason. If you drop out of a dive you will lose that money. I say this because although these dives are amazing, they can be challenging. A few divers that I dived with this weekend dropped out of several dives for various reasons. In fact, I almost dropped out of the last dive for issues with my own dry suit (that will be explained later). Dive safe my friends!!

These dives are conducted with a dive leader and several safety divers for the group.  In order for a dive leader to lead dives in the mine they are required to navigate each trail while swimming backwards underwater. Just think about that for a minute. Can you do that? A future goal perhaps.


The entrance to the dive platform

Dive 1 is Trail #1 at 51 feet deep for 49 minutes. This dive is a hands free dive for all new divers to Bonne Terre. You are not allowed to use lights or cameras (not even mounted). The dive leader uses this dive to assess everyone’s skill and comfort in this environment. At 30 feet deep everyone descends to the bottom making a semi-circle. Prior to diving the trail every diver is required to flood their mask and clear it. In addition each diver is paired up with another diver to practice air sharing.  Once these skills are completed we are able to continue to dive the trail.

Our first stop on the trail was a jack hammer embedded into the wall. It is quite fun to swim up to it and pretend I was breaking the rock, I shook it just like if I was above ground breaking asphalt on a street. Next up was an ore cart filled with broken ore and a pick ax. Go ahead pick up and take a couple of swings at the ore.

As mentioned before the only lights available are the dive leader and safety divers. The dive leader uses his lights to show us certain elements in the mine, to light our way in various directions and communicate with the other safety divers. While hovering at 30 feet deep the dive leader shined his light down below us and at 90 feet deep was a perfectly visible train. At this point, I really wish I had my camera.

Without my camera or lights in my hands, I used this time to get use my new equipment. For the first dive I over-weighed myself by a couple of pounds. I based my weight on the amount I used in Minnesota, I added 3 pounds for a total of 23 pounds.  This helps me learn my buoyancy needs to finish a dive safely (you do not want to find yourself ascending uncontrollably because you do not have enough weight). The extra weight made my buoyancy pretty tough but I managed to get through the dive. On top of that issue, I had some water leaking into my suit which filled at my feet. A fifty minute dive with cold feet makes it tough to fully enjoy the dive.  I had a few hiccups during this dive but I was still able to take in the vastness of the open spaces and the pillars.

During this dive we were able to dive under a few overhead areas with no visible access to the surface. When the dive leader shined his light on the ceiling the air pockets looked like moving mercury. It is quite mesmerizing. I would float on my back to take it all in.

Towards the end of this dive we did our safety stop at a hang bar for three minutes at 15 feet. The hang bar is located right below the dive platform. At this point I was pretty anxious to exit the water, my feet were cold and I needed to use the restroom and still had to walk a quarter mile above ground. The bathroom situation is a disadvantage of dry suit diving.

Above ground I slid my feet out of my dry suit dripping with water. Quickly dumping the water out of my boots, ringing out my undergarment to lay it out to soak up the sun before the second dive. Ah, I can not believe there was water in my suit!!

 Dive 2 is Trail #2 at 52 feet deep for 50 minutes. For this dive I dropped my weight down to 17 pounds to hopefully achieve better buoyancy control. Armed with a new pair of dry thermal socks and semi wet undergarment I was ready to start the second dive. Unfortunately I do not know why my dry suit was leaking, or where it was coming from.  At first it felt like it was coming from the top of my boots which does not give me the ability to prevent any more leaking. Wish me luck no more water gets in my drysuit. Per the dive leader’s assessment from our first dive we can use our cameras during the second half of this dive. I do not like leaving my camera behind so I was super excited to capture what I was experiencing.

With no natural light it was too dark for me to get any pictures. To combat that issue I stayed really close to the dive leader and constantly followed his lights. My pictures did not turn out but my videos turned out great. I discovered that by staying close to the dive leader I felt like it was just him and I diving alone. I never felt the presence of anyone else and it was a peaceful feeling. On each dive there are a max of 12 divers. A few times, I was kicked or hit while swimming.

To start Trail #2 we did a surface swim to the drop site to conserve our air and not duplicate trail #1. This dive consisted of a few more overhead swims. The over head obstructions were longer than than the first trail. I never felt cramped as the swim-ways were wide and big enough for several divers at the same time. Again the air pockets really grab your attention as they move like mercury when the light is shining. I do not have much experience diving with over head obstructions, although it was a unique experience I thought about what would happen if there was an emergency. What would I do? Where was the nearest “exit” so to speak and when would I see the surface again? Nothing happened during our dives, but it does not hurt to be prepared and to think about how you would handle certain situations.

At one point we swam through a hole only big enough for one diver at a time. Once through the hole it opens up into a huge area well lit from the overhead man-made lights. The vastness of the mines is beyond words, I highly suggest you experience it for yourself, you too may be speechless. Side note, Bonne Terre does offer walking and boat tours but from those perspectives I do not believe you can appreciate how far underground you can really go. From the boat, the onlookers can see the divers far below as I mentioned the visibility is 100+ feet. Something fun for non-divers.

The pillars are just massive, literally looking over the edge, the world drops off to nothing as it’s depth is beyond comprehension. The dive leader told us before the dive that he was going to show us an air volcano in which he was going to drop below the edge and use his regulator to blow air through the holes in the mine. Check out my video from my Sealife Micro HD camera.


During these dives I would put in perspective that at one point in time miners were down here doing work and here I am today breathing underwater. We came across a stair case that led to another tunnel. Check out my video from my Sealife Micro HD camera. I apologize for the moving around but I had to follow the dive leader’s lights in order to capture the stair case.

 In my first dive I had water leaking into my dry suit. Unfortunately I had to same issues the second dive. My feet were especially numb during this dive, along with my upper half as a bit more water made its way into my suit. It is hard to not feel frustrated with the cold water. I am wondering if there is something I am doing wrong or if there was something wrong with the dry suit itself. I can only troubleshoot so much without having remove myself from the next dive. Something I need to think about when this dive is finished.

Dynamite was transferred down to the mine in wood crates with Styrofoam. Since Styrofoam floats there is a ceiling in one of the rooms we dove into just littered with Styrofoam pieces and air pockets.  I never thought Styrofoam could look so artist as I badly wanted to take a picture. (I could not take a picture as we were still in the first half of the dive.)  Float on your back to take in a simple part of the history of the mine.

This is not my picture – but I thought it was important to show you the vastness of these dives and the pillars and archways. This picture is from the Gallery on the Bonne Terre Mine Website: https://www.bonneterremine.com/gallery. I could not capture this as it was too dark for my camera to pick up – but this the visibility you have when diving. Take a close look as you can see another pillar right behind the diver.

Dive #2 ends, again I make my way back above ground. First order of business is to dump out all the water in my dry suit, change socks and hit the restroom. I used this time to enjoy some snacks and re-hydrate before everyone heads down for the last dive of the day.

Dive #3 is Trail #4 at 40 feet for 55 minutes. I decided that I could drop a few more pounds to perfect my buoyancy.  Three pounds lighter, I am down to 14 pounds. I do a quick weight check in the water to make sure I can drop below the surface. Out of all five trails, Trail #4 was my favorite for several reasons. 

This dive also consisted of a few overhead obstructions and tunnels to swim through. Prior to the dive the dive leader describes in detail what we can expect for the entire dive. He explains that we will be going in what they call the Smoke Room. The Smoke Room is an area in which iron oxides in water creating underwater smoke. The iron is rusting and you can see it here. This happens all over the world but we are able to see it here because there is no current to disturb it. This was by far my favorite part of all the dives we did as I have never experienced this anywhere. I did not even know this was possible. Do you want to see a video of the smoke? I thought so! One perk of staying so close to the dive leader is that I took full advantage of his light to capture the smoke on video. This phenomena is worth sharing two videos. Please check them out as I used my Sealife Micro HD camera.

After the dive I spoke with the dive leader and told him I got some great videos of the smoke. He then told me that this was not even half the smoke there usually is in this particular room. Keep in mind if you dive here you may see even more smoke than what I experienced.

Unfortunately it was time to leave this room and on to the next adventure of Trail #4. We swam up to the counter balance elevator used to bring the ore up to the surface. Believe it or not it was easier to dump ore deeper into the mine then to use the elevator to bring it up to the surface. This elevator is as tall as one of the many pillars we encounter. One of my favorite picture from this trip was taken by one of the divers I came with. I am the diver on the left and I must give photo credit to Brian Burns (@scubapeedee). Following the dive leader we all swam through the beams of the counter balance elevator.

 I was thankful this was the last dive of the day as I was not sure I could endure another dive with a leaking dry suit. I was very cold. Back at the hotel I stood in the shower until the hot water ran out and still did not feel like I was warm enough. All three of my thermal socks were soaked and my dry suit undergarment was also thoroughly wet. We were lucky at this hotel to have access to coin laundry. I spent the night washing and drying my dive clothes to get ready for tomorrow’s last two dives.

Day Two

I just need to get through the last two dives.

Dive #4 is Trail #3 at 52 feet for 50 minutes. 14 pounds worked perfectly for me yesterday so I decided to keep it that way for my buoyancy. Today’s dive consisted of more overhead tunnels. In fact at one point the dive leader swam up to a metal grate. I thought he was going to show us something with it but it turns out we were to follow him through it. This metal grate is only big enough for one diver at a time.

Prior to the dive the dive leader told us about this air pocket we were going to explore. In this particular area there was a large air pocket (not large enough to take your regulator out and breathe but to cool enough to check out). This air pocket sits 30 feet deep in the water and was the largest we saw. So what does that do to your dive computer when its exposed to air and at depth in the water at 30 feet. I do not know, maybe nothing but if you know the answer let me know, we did not stick around long enough to find out. But I was able to take my camera into the air pocket.

This dive is not over yet. Our next stop is the Chapel Room. A very creative name for a room with white crosses painted on the walls. This room has only one way in and one way out. Stay near the exit if you get nervous, but nothing to worry about. The dive leader will light your way.  I believe this where the miners were marking for dynamite but I could be wrong. You will see the air pockets on the ceiling (looks like mercury). I apologize for the moving around in this video but I had to follow the dive leader’s lights, as I had no lights.

Speaking of dynamite. The dive leader took to an area in which you can see a stick of dynamite embedded into the wall of the mine. I think I can safely say this was the first time I have seen a stick of dynamite in person. 

My buoyancy skills were on point for this dive but the flooding was getting worse. At this point water is up to my calves just sloshing around as I kick with my fins. I am trying to ignore the cold water but it is not easy when you can not feel your feet. During the dive we are swimming with a ceiling overhead, I have spoken of air pockets all through out this trip but in this particular dive we swim to the level above the ceiling we were under to witness our air bubbles rising through the mine in slow trickles.


Dive #4 comes to end and I am thinking I will sit out the next dive. I do not think I can handle anymore water. Plus the flooding is getting worse with each dive.  Back to top side to pour out all the water in my suit. I will tell you the suit holds water in very well. Another change of the thermal socks. Thermal socks do not work well when wet. But at least with each new dive I start off with a dry pair.

Debating on my next move. To dive or not to dive? That is the question. In the end, I decide that I will dive. I traveled a long way, and spent quite a bit of money to experience Bonne Terre. At least that was my rational. I also thought if I can make it through 20 minutes of the 50 minute dive I can still count it as a dive and I would be happy with that.

Just before heading back underground, a fellow diver asked if I wanted to use some duct tape around my wrist. I said “of course!” It couldn’t hurt right? And it might help me determine if this is where the leak was coming from. My hike down I eagerly carried a roll of duct tape thinking I have nothing to lose.

By dive #5 I have my routine down to get ready for the dives. This one included duct taping my wrists. I did two layers of duct tape on each wrist to just be on the safe side. Geared up and ready to go, I did my last giant stride into the water, hoping I can make it 20 minutes.

Dive #5 is Trail #5 at 67 feet for 43 minutes. At this point I have documented a lot of videos. Mentally I was keeping my focus on staying warm and trying to determine where my water leaks were occurring. I still have yet to figure that out. Even with a new pair of dry socks, as soon as I put my dry suit on my feet were wet with the residual water from the last dive. This dive had the most overhead, cave or tunnel swim throughs. The dive leader did not use his lights as much which made it difficult for me to take videos anyways, so I enjoyed the dive following the glow stick of the tank in front of me.

There is a lot of history in the mine and below the water. It is amazing to see little snapshots of that history while diving. When the pumps were turned off the mine flooded, with that many items in the mine floated to the ceiling of that particular room they were housed in. In this video you will see light bulbs that are still in the mine. A random every day item found 130 below the ground.

This was the only video I took on dive #5. To my surprise this dive was the most comfortable dive for me. I achieved my 20 minute goal and completed the entire dive. My feet were wet but not soaked. I should have used duct tape after dive #1 and maybe I would have enjoy the dives even more. Note to self: bring duct tape. My spirits were lifted a bit as maybe I solved the mystery of my water leak. Nevertheless, as soon as I get back to Virginia Beach, I will be working with my local dive shop to determine the issues I endured throughout my dives. If I had these issues in Antarctica I probably would have died. I am grateful this happened now as this is all part of my training and preparation for Antarctica. I am learning the ins and outs of my dry suit and working out the kinks. (I will share my results in the next dive blog, stay tuned.)

One additional side note in terms of my equipment use. Prior to this trip I purchased 2 pairs of gloves one pair 5mm and the other pair 7mm. I could not decide on which thickness I wanted and should bring, so I brought both. The first three dives I used my 5mm gloves. My hands were cold after the first dive and by the end of the day my hands were numb. Day two, I dove with my 7mm gloves to see if there would be additional warmth and if there would be any dexterity issues as they are thicker gloves. My hands were not nearly as cold as the first day, and luckily I did not have any problems with dexterity as I used my camera throughout the day.  Also I had absolutely ZERO issues with my Aqualung Glacia cold water regulator, in fact the lip guard on the mouth piece was essential in keeping my mouth/lips warm. It really made a difference and I would highly recommend any diver to get the mouth guard for cold water diving; it is easy to slip on and well worth the small investment.

Overall, Bonne Terre is a fantastic experience for many reasons. There are not many places in the world can you dive underground and then go underwater even further.  A lot of learning lessons for me. This was my first real test in my cold water training. I look forward to the next opportunity I can make it out to Bonne Terre and dive trails 6 through 10.  If you made it all the way to end of this blog, I applaud you as this was a long post but to me worth writing to share my experience. Thank you for your time! If you have any questions please feel free to contact me or follow me on Instagram @lockhart0416.

A special thank you to Nautilus Aquatics (http://nautilusva.com/) – the dive shop that let me join this trip at the last minute, as well as Brian Burns and Andrew Bodyk for leading the trip and really showing us a good time! I hope to dive with you again, and with the other divers I met this weekend. Future dive buddies!!! 

Added five more dry suit dives towards my goal of 30 by February 2019 for Antarctica. This brings my overall total to 10. 

This is the third installment of Shannon’s blog on her road to diving in Antarctica. You can read more about her adventures here; Diving Antarctica 2019, on her website or her Instagram. – Editor