Surge of frolicking whales prompts boating warning off San Francisco

• 115 humpback, fin and blue whales spotted in one hour near Farallon Islands
• Recreational boaters told to stay 300ft away from feeding giants

Dozens of whales are frolicking off Northern California's coast in a feast for the eyes that has also prompted federal officials to issue a boating warning.

Officials documented 115 humpback, blue and fin whales during a one-hour survey last weekend near the Farallon Islands, the Marin Independent Journal reported on Saturday.