The explanations about how Ukraine blew up the Nordstream Pipeline remind me of the explanations for how coconuts were brought to England by swallows in Monty Python and the Holy Grail
Really, it’s not difficult.
It’s more like bringing coconuts to Britain via the Paris-London Eurostar.
https://www.eurostar.com/rw-en/train/uk/paris-to-london
The Baltic is shallow and the pipeline location is well marked, we all have GPS these days, bottom scanning sonar is ubiquitous (do you want to see marketing materials?), and all it takes to rupture a pipeline is a damned simple bomb with a timer.
It’s not the Dambusters raid.