The crew worked at a feverish pace in order to be ready, and by the time "Kronprinz Wilhelm" met "Karlsruhe"s tender—SS "Asuncion"—near Rocas Reef north of Cape San Roque on 3 September, preparations were nearly complete. At 20:30 the following evening, the auxiliary cruiser encountered a target, the British steamer . The merchantman stopped without the raider's firing a shot. Heavy seas, however, postponed the boarding until shortly after 06:00 the following morning. The prize crew found a cargo composed largely of contraband, but before sinking the ship, Commander Thierfelder wanted to salvage as much of her supplies and fuel as he could. Continued heavy seas precluded the transfer until the afternoon of 8 September. "Indian Prince"s crew and passengers were brought over to "Kronprinz Wilhelm" at around 14:00, and the two ships moved alongside each other immediately thereafter. Coaling started and continued throughout the night of 8/9 September. The following morning, the German prize crew detonated three explosive charges which sank "Indian Prince". "Kronprinz Wilhelm" then headed south to rendezvous with several German supply ships.