[sschueller]

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.

[Dma54rhs]

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.