Across the Korean peninsula, the east coast Allied offshore island defense centered on a cluster of islands in Wonsan Harbor. Situated more than 100 miles north of the battleline, these strategically-placed islands comprised the northernmost UN-held territory in Korea. The East Coast Island Defense Command numbered approximately 35 Marines, 1,270 Korean Marines, and 15 Naval personnel. Headquarters for TU 95.2.3 was Yo-do, the largest installation, which was garrisoned by approximately 300 Korean Marines and a limited detachment of USMC and USN personnel. Smaller defense forces were located on the other islands under ECIDU command.[470] In addition, an improvised NGF spotting team was also stationed at the three forward islands (Mo-do, Tae-do, and Hwangto-do). Mission of the ECIDU was a defensive one: to hold the islands as a base for covert intelligence activities. The island defense system existed for the purpose of “containing and destroying any enemy forces who escape detection or who press home an attack in the face of Navy attempts at their destruction.”[471] [470] See Chapter II and ECIDE map. [471] ECIDE ComdD, Oct 2, p. 1. Individual island commanders were responsible for the defense of their small parcels of seaborne real estate, control of both defensive and offensive NGF missions in the area, and evaluation of intelligence regarding enemy troop locations, the movement of supplies north, or new emplacements of hostile guns. Fire support for the ECIDU islands, exposed to the enemy shore batteries above the 39th Parallel, was available from Task Force 95, which maintained a task, group of ships off both the east and west coasts. Aircraft and ships of Task Force 77 (Seventh Fleet Striking Force), operating off the East Korean coastline, were also on call. In December, for instance, the Corsairs of TF 77 had resumed their rail-bridge interdiction. All-out attacks on railroad and highway bridges, as well as bombing runs on the 90-mile stretch of east coast railroad from Hungnam to Songjin, were undertaken to cut off supplies being moved north for Communist industrial use. February marked the second anniversary of the siege of Wonsan by the UNC, the longest blockade of a port in recent U.S. history. Some naval authorities by this time argued that the venture had become one of doubtful merit which “should never have been undertaken, but its long history made it difficult to abandon without apparent admission of defeat.”[472] In any event, the month also signaled increasing attention paid by hostile shore batteries to the little island enclave. For seven consecutive days, 9–15 February, the harbor islands were targets for enemy mixed artillery and mortar shells. Minor materiel damage and casualties were sustained at Yo-do during a Valentine’s Day bombardment, 14 February. [472] Field, _NavOps, Korea_, p. 434.