“The Ukrainians doing in Nordstream was my first take from last year. It’s not that hard.”
Yep, and they swam out there, under the radar, with their fins and snorkels.
Why are you even posting anything here?
“Why are you even posting anything here?”
Because I’m bored and you are being silly.
As for how - no, they sailed there, in a ship. They found the pipeline through its publicly given GPS location in marine charts, well plotted for navigation safety reasons. Fine plotting could be by commercial sonar. Drop divers, lower the bomb over the side, divers guide bomb into place by giving directions to the ship, set the timer, and there you go.
This sort of thing is SOP in marine engineering.