Two sinking boats in San Francisco Bay Friday morning prompted the U.S. Coast guard send a search helicopter to look for victims, only to determine the vessels were empty when they went down. The two small boats, one which appeared to be a sailboat, were found in the waters off Sausalito and Berkeley, said Petty Officer Cory Mendenhall of the U.S. Coast Guard, adding that Thursday’s rainy weather could have contributed to the boats sinking. No other details were immediately available. Sarah Ravani is a San Francisco Chronicle staff writer. Email: sravani@sfchronicle.com Twitter: @SarRavani
