from "KTVU.com" television news [http://www.ktvu.com/news/news/local/humpback-whales-frolic-san-francisco-bay/nSQtF/]:
SAN FRANCISCO — With temperatures soaring in the Bay Area Monday, a pod of three migrating humpback whales were among the many who sought relief in the San Francisco Bay.
The whales were seen inside the Bay around 10:30 a.m. and swam around for about 30 minutes before going under the Golden Gate Bridge and continuing their journey in the Pacific.
This time of year, the humpbacks – known as the acrobats of the seas – generally are traveling south to Mexico or to the Hawaii Islands.
Both male and female humpback whales vocalize underwater, but only males produce the songs for which the species is famous.
The Bay Area was home to one of the most famous humpback whale sightings in history.
Humphrey swam into the Bay and up the Sacramento River to Rio Vista where it became trapped in 1985. Sausalito’s Marine Mammal Center rescued and tagged it but the wayward whale returned five years later and became stuck on a mudflat near Candlestick Point.
Using a large cargo net, he was pulled free and again guided back to the ocean. Humphrey was last seen near the Farallon Islands in 1991.