It had been simple. He distributed the little packs of C4 with their radio detonators as he made his rounds on the huge ship. After he finished, he went up to the con tower and handed a copy of his inspection report to the first mate. He then made the long way down and around, disembarking in time to beat the crowd of tourists.
Somewhere off the coast of North Carolina they detonated the bombs. There were seven survivors.