The article literally does describe how divers would do so with quotes from a subject matter expert: >Achim Schlöffel, a German extreme diver who runs a diving

The article literally does describe how divers would do so with quotes from a subject matter expert: >Achim Schlöffel, a German extreme diver who runs a diving school and helps companies protect vessels and underwater installations from sabotage, said explosives could have been planted by a group of well-trained technical divers accustomed to working at such depths—around 80 meters—assuming they had several days to do so. >Six divers, he said, could have lowered the explosives in several dives using commercially available equipment such as underwater scooters or propulsion vehicles, airlifting bags and buoys, and a portable sonar. “I know dozens of professional divers who would be up to the task,” Mr. Schlöffel said.