The Cyane was commissioned in July, and sailed from Norfolk on the 10th of August, 1845, under Captain Wm. Mervine, destined for the Pacific station. After calling at Rio Janeiro, Valparaiso, and
Callao, she reached Mazatlan, on the west coast of Mexico, in January, 1846, where she found the American squadron, under Commodore Sloat, watching the course of events in that republic.
A few weeks after, a special messenger arrived from the United States, who was conveyed in the Cyane, first to the Sandwich Islands, and thence to Monterey, in Upper California; the ship immediately rejoining the Commodore at Mazatlan on the 30th of April, where she found, in addition, the English Rear-Admiral with his line-of-battleship and two other vessels of his fleet, having, it was supposed, an eye to the movements of the American Commodore.