She performed routine duties in the lagoon at Bikini until the afternoon of 24 July, when she again departed to observe the shallow underwater detonation (Test Baker) from a vantage point 25 miles to the east. Following the Baker blast, Ottawa proceeded to Rongelap Atoll, about 65 miles east of Bikini, and with the exception of a two and a half-hour visit to Bikini on 28 July, did not return to the waters inside Bikini lagoon for any length of time until the last day of July. Wrapping up her work in those waters with JTF-1 on 2 August, she sailed that day for Port Hueneme, arriving there on 14 August and being released from "Crossroads" simultaneously.
She carried out routine duties in the lagoon at Bikini until July 24, when she moved east for an underwater detonation (Test Baker). After the Baker blast, Ottawa visited Rongelap Atoll and only returned to Bikini once more on July 28th. She completed her work with JTF-1 on August 2nd before sailing to Port Hueneme.