"Rainbow" shifted from Olongapo to Cavite on 8 October 1912 and served there as temporary flagship for the Commander-in-Chief, Asiatic Fleet (30 October-7 November). She departed Cavite on 7 November 1912, bound by way of Woosung, Shanghai, and the Yangtze River to Nanking, China. She arrived at Nanking on 20 November and sailed 10 days later to cruise with the American ambassador to the ports of Shanghai, Hong Kong, Swatow, Amoy, and Woosung. She departed Woosung on 28 December 1912, investigating the landing facilities at Lingayen Gulf in the Philippines before being repaired at Olongapo in January 1913.