ROSTOCK, Germany—The small marina on the sting of this north German metropolis is a well-liked summertime spot for leisure sailors. German intelligence believes it was additionally the jumping-off level for the sabotage of the Nord Stream gasoline pipelines,
an assault on Europe’s civilian power infrastructure unprecedented since World Struggle II.
On Sept. 6, a small group set out from Rostock aboard a rented yacht, the Andromeda, a slender 50-foot-long, single-masted sloop, ostensibly on a pleasure cruise round Baltic Sea ports. Inside two weeks, the group returned the boat and disappeared.