Shortly thereafter, "Berkeley" moved to a surveillance position about 25 miles to the south and kept foreign merchant shipping informed of the newly cordoned waters. In mid-June, an attempt by the North Vietnamese to ferry supplies ashore was foiled when "Berkeley", supported by helicopters and two other destroyers, sank over 30 small craft. After a brief upkeep period at Subic Bay in mid-July, the guided missile destroyer moved to the gunline and fired daily missions against enemy targets near the DMZ. Following a short yard period at Sasebo late in August, the warship conducted a final five-week gunfire support tour off North Vietnam.