"Grapple" cleared Kwajalein, staging area for the Guam assault, on 15 July, then 6 days later was standing off Guam in support of the first wave of assault troops. Her vital salvage work at Guam included pulling stranded landing craft off the beaches and repairing damaged ships, usually within range of enemy fire. Demolition crews from "Grapple", also performed the important work of clearing the Apra Harbor entrance of a Japanese freighter sunk by American bombers. After the consolidation of Guam, "Grapple" returned to Espiritu Santo via Eniwetok for repairs and preparation for next major assault.