"Shelter" then continued to Tinian for supplies and then escorted USS "Guide", flagship of COMMINEPAC to Iwo Jima that arrived off the island on 16 February 1945. She made pre-invasion sweeps with Mine Division 36 consisting of six ships, which were ordered to fire on shore, and to retire if fire returned which it did, possibly because one of the other ships destroyed a Japanese radar emplacement. A larger ship then attacked the revealed emplacements. Troops stormed ashore on 19 February and the "Shelter" remained on patrol and screening station until 28 February; then helped guard an amphibious (damaged LSTs) group to Saipan before proceeding to Ulithi, Western Caroline Islands, arriving on 9 March for logistics and preparations for the coming Okinawa campaign. At an unknown time prior to Okinawa, USS "Shelter" was refitted to add a combat operations center, which replaced the captain's bunk on the bridge (one level below the flying bridge). This was a possible reason for recommissioning in 1964. "Shelter" had only surface radar, so incoming flights were relayed with a bearing and the estimated time until arrival from a point ashore. This was converted to a bearing and time to arrival at "Shelter" and relayed from "Shelter" to the other ships in the battle group.