SAN FRANCISCO (AP) -- Boaters are being warned to steer clear of a mother gray whale and calf that wandered off course into San Francisco Bay during spring migration.

The whales were seen surfacing Wednesday off San Francisco's Crissy Field at the foot of the Golden Gate Bridge.

Federal wildlife officials say witnesses observed one incident where a small boat sped toward the whales, forcing the pair to get out of the way.

Farallones Marine Sanctuary spokeswoman Mary Jane Schramm says boaters who harass whales could face civil and criminal penalties.

Thousands of gray whales migrate each spring from calving grounds off the coast of Mexico to their feeding grounds in Alaskan waters.

Several whales typically find their way into the bay each year. Schramm says gray whales typically swim closest to shore.