Marie Agnes is a very specific dive site. Narrow corridors make it almost impossible to navigate using fins. We suggest to dive with using a French configuration - weight belts and 2 side cylinders rather than classical sidemount harness or twin setup. Please keep in mind that although small, this object can be very dangerous due to extremely quickly dropping visibility and narrow passages, so enter only if full-cave certified.
The good thing is that if you’re the only one(s) diving here, you can park your car right next to adit mouth. If you’re not that lucky however, it’s best not to dive at all and wait until the next day. After each dive the amount of silt in the water causes the visibility to drop drastically. The object is also way to small for 2 teams to dive simultaneously
Now for the hard part. You need to transport your gear into the mine. It’s not as hard as it may seem from the outside. The adit mouth is no more than 1m high (3ft) so you have to squeeze in somehow. Personally I prefer to carry one cylinder at a time, but some of my friends simply take small, 4l sidemount cylinders and enter fully kitted up, heading straight to the water. After passing the narrow entrance, you can expect around 180-200cm height. Watch out however, the tunnels are highly irregular. At the very beginning you will find a T-junction - take the left turn and go around 50m down the corridor. You will end up in a chamber accessing the main vertical shaft - that’s where you dive.
We start descending by the main shaft. As soon as we reach the bottom (10m/30ft) we enter the left (short) corridor) Notice the wooden reinforcing above your head - this is an artificially built platform on which part of the excavated materials is being stored. It’s up to you whether you want to go back the same way, or try to squeeze through the very narrow opening above the wooden ceiling. Keep in mind you might be forced to push your cylinders in front of you.
Now it’s time for the right-side corridor. Start by diving into the lower one, at the very bottom. Once again you will see the wooden reinforcement right above you. What’s really cool though it that at the end of the short corridor you’ll be ascending through a timber winch construction that was used to extract the excavated material. You can now explore the longest corridor (+- 6m/18ft depth). This is also the place where the tunnel reaches its maximum height - around 3m/9ft. When finished, turn around and go back all the way - you will leave the wooden winch on your right hand and reach the main shaft shortly after that. It’s time to slowly ascend to the surface.
Enjoy and safe dives!
