You didn't read the article, huh? It's all laid out there, from the challenges of those deep dives to the possible CIA involvement to the shaky cover story.
specialized gear, and advanced certification—far beyond normal recreational scuba capabilities.
In the article, they even go in to detail that even Navy divers rarely dive that deep so:
To assemble the Diameter team, however, the men had to reach outside their usual battle-hardened ranks, and recruit specialist, civilian deep-sea divers – the only people capable of going down to Nord Stream’s 80-metre depth. Luckily, Ukraine has a large and patriotic Black Sea diving fraternity, from which volunteers were picked amid great secrecy.
This entire article reeks of cia
So much so they hint at their own involvement? Classic cover story. "We distract from our involvement by hinting that we might've been involved!"
Pancevski hints that the CIA might have given the Ukrainians tacit encouragement. “Not all senior CIA officials who got wind of Operation Diameter were outraged,” he writes. “They weren’t necessarily averse to someone putting the pipeline permanently out of commission.”
Shooting porn at deeper than 40meters is no cover story anyone would believe.
That was an idea that was floated earlier in the planning phase of the operation.
They then travelled to Germany, where they hired a boat from a marina on the coast and posed as leisure divers exploring shipwrecks. (The Colonel’s suggested porn-film alibi had, at this late stage, been abandoned.)