At the end of this, on 19 June, the patrol frigate headed south to San Diego, where she engaged in a month of shakedown training.

On 21 July, she completed that training and began post-shakedown availability at Alameda and Oakland, California.

[3] Brownsville spent her entire, brief Navy career assigned to the Commander, Western Sea Frontier.

She conducted barrier patrols and escorted coastal shipping in addition to amphibious training and anti-submarine warfare exercises.

That duty, punctuated by repair periods at Treasure Island, lasted until 15 April 1946, when she was decommissioned, turned over to the Coast Guard on a loan basis, and commissioned as USCGC Brownsville.