Johnson saw the mines being brought on board the Enterprise from the ammunition ships. “They were all packed in wood crates,” he recalls, “and they looked like garbage cans. And we wondered how an airplane could ever get off the flight deck of a carrier carrying those garbage cans.”
D.E. “Moose” Wheelock, a former member of the mobile mine assembly team, later wrote about the 1967 mission for the Association of Minemen. His job was to coordinate the setup to receive the mines and upgrade them for aircraft mining operations. When he arrived on the Enterprise the day before the mission, he met with the Operations Commander, who was very concerned about the arming depth of the Mk 50 mine (the depth at which it could detonate). Wheelock knew that 12 feet was the arming depth, but suddenly wondered about the tidal variations in the rivers. The mission was scheduled for 2200 [10:00 p.m.] on February 26. After learning that high tide, which would occur at 2230, added another 6 feet, the arming depth was changed accordingly.