SAN FRANCISCO (KCBS) — Two gray whales have been spotted inside the San Francisco Bay.

The Coast Guard says it’s closely tracking the two whales, to make sure they are safe.

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They are urging boaters near Angel Island and the Golden Gate Bridge to be especially careful.

U.S. Coast Guard spokesman Jacob Aulner said the whales were seen swimming from Alcatraz to Angel Island around 2:30 p.m., Saturday afternoon.

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“We sent out a broadcast notice to mariners, essentially saying… there are whales in the Bay and to transit with extreme caution and stay outside of 100 yards from those marine mammals,” said Aulner.

A marine mammal expert told KCBS said he believes the two whales are likely a mom, and her calf.

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Any boater, or person on shore who sees the pair should contact the Coast Guard right away.