Rumor seemed to have the support of fact on this occasion, for compass readings left no doubt that the armada had indeed executed a maritime “about face” to head southward. What the men on the transports did not know was that the reversal of direction had been ordered for purely military reasons as a result of the conference that day on the _Missouri_. It was puzzling enough to the troops the following morning when the ships resumed their original course. But this was nothing as compared to their bewilderment late that afternoon as the Tractor and Transport Groups turned southward again. Every twelve hours, in accordance with the directive of CJTF-7, the fleet was to reverse course, steaming back and forth off the eastern coast of Korea until the last of the magnetic mines could be cleared from the lane in preparation for an administrative landing at Wonsan.[80] [80] ComPhibGruOne, “Operations Report,” 12; Smith, _Notes_, 404; Struble Comments, 16 Mar 56. Marines have always been ready with a derisive phrase, and “Operation Yo-Yo” was coined to express their disgust with this interlude of concentrated monotony. Never did time die a harder death, and never did the grumblers have so much to grouse about. Letters to wives and sweethearts took on more bulk daily, and paper-backed murder mysteries were worn to tatters by bored readers. On the 22d, at CJTF-7’s regular daily meeting, Admirals Struble and Doyle conferred in the destroyer _Rowan_ with Admiral Smith and Captain Spofford. It was agreed that the sweeping could not be completed until the 24th or 25th, which meant that Operation Yo-Yo might last a week.[81] [81] ComPhibGruOne, “Operations Report,” 12; Struble Comments, 16 Mar 56. The situation had its serious aspects on LSTs and transports which were not prepared for a voyage around Korea taking nearly as long as a crossing of the Pacific. Food supplies ran low as gastro-enteritis and dysentery swept through the crowded transports in spite of strict medical precautions. The MSTS transport _Marine Phoenix_ alone had a sick list of 750 during the epidemic. A case of smallpox was discovered on the _Bayfield_, and all crewmen as well as passengers were vaccinated that same day.[82] [82] _Ibid._, 11; 1stMarDiv _SAR_, annex VV, (hereafter 7thMTBn _SAR_), 2; ComPhibGruOne msg to BuMed, 0034 27 Oct 50. On the 23d, as the _Mount McKinley_ proceeded into the inner harbor at Wonsan, there could be no doubt that the final mine sweeping would be completed by the 25th. Operation Yo-Yo came to an end, therefore, when Admiral Doyle directed the amphibious fleet to arrive on the 25th, prepared for an administrative landing. The order of entry called for the Transport Group to take the lead, followed by the vessels of the Tractor Group.[83] [83] CTF 90 msg to CTG 90.2, 1119 24 Oct 50 in G-3 Journal, X Corps _WD_ 10–25 Oct 50.