It's been reported that the pipeline is encased in concrette which had to be removed before placing the explosives. Additionally several ships with proper diving gear and crew had to go there and stay undetected.
That is not true. Seismic monitoring show that the explosions were equivalent to several hundred kilograms of explosives. With that much explosives there was no need to remove the concrete. The "concrete removing CIA robots" narrative is only pushed by Russian propaganda accounts.
Where do you get that amount of explosives that can be used under water and not be questioned at time of purchase?
I didn't read about robots but divers that had to jackhammer under water.
We are talking about nation states, it's a silly question. Neither Russia, USA or any other state has a problem "buying" the explosives. They don't shop in the fertilizer section at your local hardware store.
It's in the Baltic.
Truth, that is what I meant. The Baltic Sea is generally not that deep was the point. It does not require advanced marine navigation or diving equipment to reach the pipeline