The former fleet surgeon William M. Wood and John Parrot, the American Consul of Mazatlán, arrived in Guadalajara Mexico on 10 May 1846. There they heard word of the ongoing hostilities between the U.S. and Mexico forces and sent a message by special courier back to Commodore Sloat then visiting Mazatlán. On 17 May 1846 this courier's messages informed Commodore Sloat that hostilities between the U.S. and Mexico had commenced. Commodore (Rear Admiral) John D. Sloat, commander of the U.S. Navy's Pacific Squadron and his fleet of four vessels were then at anchor in the harbor of Mazatlán. On hearing the news Commodore Sloat dispatched his flagship, the frigate , and the Sloop to Monterey harbor where they arrived on 2 July 1846. They joined the sloop which was already there. There were U.S. fears that the British might try to annex California to satisfy British creditors. The British Pacific Station's ships off California were stronger in ships, guns and men.