Finally, the first day of The Maria Concordia Project has come. Driving to the site, I repeat my checklist engraved deeply in my memory. I go through each part of my diving gear - I remember vividly when and where I put it in the trunk.

Then goes the second checklist, related directly to the scanning process. Do we have six cameras? Yes, two of my own, three that I ordered from the rental company that I received this morning, and one that Bartek is going to bring with him. Check. Camera batteries and chargers? Check. I have thirty batteries and sixteen charging slots. How about memory cards? We need at least ten of those: three of my own, six from the rental company, two from Mateusz, and one from Bartek. Check. Ok, so how about lights? It looks like we are prepared here, too. I have a set of four primary video lights with a double battery set, and four backup video lights with a dual battery pack. I also have a bag of chargers that will allow us to charge all 32 batteries simultaneously. Paweł has another set of four video lights with a complete set of batteries. This complete set will allow 5-6 scanning dives daily without worrying about the lights or camera batteries. 

Ok, it looks like everything is good to go. 

So how about the team? All is good here as well. Mikko, who is in Poland for just a few days, was complaining he won't be able to get his hands on a decent dry suit, but eventually, thanks to our friends, he's got more than one. Even Michal, our photographer who turned sick a few days earlier, got better and is coming this evening. Let's do it! 

A few hours later…   

I've got to admit - when things start to go wrong, they go wrong all at once  

- Michał (the photographer), who thankfully recovered before D-day, twisted his ankle when packing the car and, in the end, is not coming. 
- Paweł, who was supposed to be the backup diver, got cold and could not dive. 
- One GoPro refused to work without any technical explanation during our first dive. 
- Three of our memory cards decided they will not work with the rented cameras today. 
- During the first dives, we had some drysuit leaking issues. 
- When assembling our scanning device, I cut my hand pretty badly.

This is the moment when you understand that having a plan B is not enough. Having a plan C, D, and E becomes necessary. So we began to solve the puzzles one by one.   

- First, we sent some words of support to Michał - I know how he must feel right now. We will take some good underwater documentary shots during our next scanning meetup here in a few months. We must return here anyway; there is no way of doing the scan 100% properly the first time. In the meantime, Mikko will take photos of me scanning the corridors. 

- Bartek has bought some extra memory cards on his way to the mine. Fortunately, we noticed this problem soon enough. 

- We decided to do nothing about the broken GoPro. After a bit of tweaking of our scanning rig, we managed to get enough overlap for all the other cameras. It might be good; we will have tons of photos anyway. 

- The drysuits also proved to be fixable, at least the one from Bartek. Fortunately, Mikko had another backup one, thanks to our friends from SEAL Drysuits, and that one proved to perform outstandingly. As for my leak, I decided not to care. It wasn't that bad; I had dived in worse conditions before.  

After overcoming those little obstacles, the following days went surprisingly well. It almost felt as if the mine itself was asking us: 'Do you have what it takes to pull it off? Or will some little inconveniences make you cave'? 

Of course, the real challenge started when we went back home and started the reconstruction process using over 100,000 photos we acquired on our dive, but this fight deserves a story of its own.