Expert Discusses Deep Cave Diving Challenges and Equipment

Some argue that currents could have been strong enough to create suction inside the cave...

I can only comment based on my experience. We have experienced these so-called tidal currents. The water moves in one direction for 12 hours and then in the other for another 12. Continuous currents. On the coral reef, it is very predictable. When we entered the cave, we perceived a very slight current inside. So it is true that there is an inflow and outflow current in the cave. The cave, so to speak, breathes. But it is really very weak. It is not possible that it has sucked someone in.

What were the main obstacles or difficulties you encountered when entering this cave?

First of all, it is a rather deep cave, over 60 meters. And being a cave, it requires techniques, gases, and special equipment to be able to enter it. So there are many small details that must fall into place to be able to perform this type of dive or even any work inside it. We are not the only ones capable of carrying out this type of rescue. There are many competent people in the world. But you have to take into account all these characteristics: be trained, have the right equipment, and the necessary experience to perform this type of work.

What are these fundamental equipment?

To dive to more than 60 meters, you need diving gases besides air. They are called trimix. They are a mixture of oxygen, nitrogen, and helium, which reduces the effect of narcosis at depth. This way you stay lucid and can work more efficiently. And in addition to trimix gas, we use a device called a rebreather, which recirculates our breathing gas, giving us a lot of time inside. In rescue operations, you don't know how long you will stay at the bottom, and it is essential to be able to stay almost as long as necessary. We have an autonomy of more than five hours, up to ten if we push the limits. Now, however, we limit our dives to three hours. It is much more than what can be done with conventional diving equipment.

With conventional equipment, how long can you stay underwater?

Only a few minutes, 10 at most.

I know you cannot talk about what happened down there, but can you say if the problem was also the lack of these instruments?

I cannot speak directly about this case, because there is an ongoing police investigation. But I can speak in general about deep and cave diving, because I am also an instructor for this type of diving. To dive to such depths and inside a cave requires a different type of equipment and approach. And perhaps also different gas mixtures.

That they did not have?

I don't know what kind of gas they were using, because the police will investigate it. So I cannot comment on that.

But you recovered their equipment and handed it over to the police, like the GoPros...

We recovered the people, which was priority number one. Obviously, they were wearing all their diving equipment. So everything was brought to the surface and handed over to the police. I cannot specify what items they were carrying or what was handed over to the police, but everything they had was handed over to the authorities.

How does one psychologically prepare to enter a cave?

Cave diving is never easy. It requires more careful planning than a normal dive. I have the privilege of having practiced deep cave diving for almost twenty years. So I rely heavily on the experience and knowledge gained. However, I always plan every dive. And I cannot say it was a walk in the park. So we put in a lot of effort... When we received the call to join the operation, we started gathering information about what we needed for this type of dive. And little by little we reconstructed the puzzle of what was necessary: what gases and what support. DAN Europe was very helpful in organizing everything, in collaboration with the Italian embassy, the Maldivas defense forces, and the local police.

So, did you feel safe?

We felt safe. You should never do a cave dive if you are not sure of the outcome. We are a very experienced team, which has performed numerous cave dives, even very demanding ones. We all participated in the Plura cave rescue project, in Norway, in 2014. It is a very cohesive team that has already performed similar work before. So I was confident that we could complete the operation.