Vella Lavella, made up the southern branch of the Solomon Archipelago, constituted the second rung on the ladder to Rabaul. While Waters waited for the assault on that island, scheduled for the end of June, she patrolled the anchorages of Ironbottom Sound between Guadalcanal and Florida Island. On 16 June, she fought her first action when attacking Japanese planes dropped a stick of bombs close aboard. She returned the compliment more accurately than her adversaries, as her antiaircraft battery splashed two of the offending bombers. Four days later, she received orders to move to Guadalcanal to embark five officers and 187 men of the 4th Marine Raider Battalion, part of a force hastily collected to occupy Segi Point on the southern coast of New Georgia. The Japanese were then moving in on a coastwatcher named Kennedy who held the plantation on the point, and Rear Admiral Richmond K. Turner decided to advance the date of the opening of the Segi Point phase of the New Georgia operation in order to keep possession of the beachhead which for all intents and purposes was already established there and to protect Kennedy and his native guerrillas. Waters and Dent transited the Slot during the night of 20 and 21 June and, early the next morning, threaded their way through the uncharted shoal water between New Georgia and Vangunu to Segi Point. In less than two hours, the two former flushdeckers disembarked their passengers and stood out to sea again. After a daylight passage back down the Slot, Waters and her sister ship returned to Guadalcanal late that afternoon and thence moved to Port Purvis without incident. On 25 June, Waters moved to Guadalcanal to embark more troops, this time the "Barracudas" scout troops of the Army's 172nd Infantry. Until 29 June, she practiced amphibious landings at Purvis Bay; then headed north for the landings on Rendova, a small island south of New Georgia and directly opposite Munda, the main objective of the operation. The troops she carried were to have led the assault on Rendova and to have secured a beachhead for the main invasion force. However, heavy weather obscured the beacon fires which were to have guided them ashore, and the "Barracudas" landed some down the coast from their objective. By the time they reembarked and moved up the coast, the troops were able to land unopposed across a beachhead already established