SAN DIEGO (CBS 8) - Shark sightings aren't that rare off the California coast, but what happened recently in San Francisco Bay is.
People on two bay cruises saw a Great White attack and kill a sea lion just a few yards from Alcatraz Island.
It's believed to be the first recorded shark attack in the bay.
In to the water and then out of water, you can see a great white on the hunt, and its prey a seal lion barely hanging on.
Crowds of people docked on two separate Alcatraz cruise ships stand in amazement as the shark shows off.
"They oftentimes breach because they are stalking that seal, so they're coming up and they're getting a lot of momentum and then they're grabbing the seal so it is a usual behavior," said shark diver, Cindy Michaels.
The water around San Francisco Bay is shallower and made this particular kill with all the blood around more unusual for a shark to be there.
"As you get toward Alcatraz, I think it ranges between 15 to 40 feet. Which is typically shallower for Great Whites to live in, which is why this is kind of weird as to why they are there. They're fast, they're fast and they can move fast straight and upwards as well," said Michaels.
But it's still not uncanny for sharks to be that close in the San Francisco Bay, but certainly different that this one was so close to the ships.
"So that's an aggregation site for Great Whites. They breed there. They meet there, so it's not unusual for one to venture into the bay, what's unusual in this case is that it was documented," said Michaels.
It is normal behavior for sharks to attack seals.
"This particular shark was probably around ten-feet. It's turning into an adult, so it is going after seals, which is their normal meal. Adults eat sea lions, younger sharks eat fish," said Michaels.
The video was taken from surveillance of Alcatraz cruises as tourists pointed and one little boy was stunned.
"But this is just a natural order of things. Unfortunately seals are cute, and we don't want them to die, but they are food source for the sharks," said Michaels.
The first attack video went viral in three days with close to one million views. The latest shark attack video has that many views in just 24-hours