Earlier this week we reported that tourists visiting the island prison of Alcatraz witnessed something few have ever seen: a great white shark predation of a seal or sea lion inside San Francisco Bay.

Some video of the aftermath of the incident and a little boy who got caught up in the excitement went viral.

RELATED: Alcatraz Tourists Gasp As Great White Shark Attacks Seal in SF Bay: WATCH

Now, there is some new incredible video which was taken from a stationary camera on the Hornblower Cruises tourist boat.

The video shows the great white shark LEAPING from the water with the seal in its mouth.

Watch:

This is the first-ever recorded attack inside San Francisco Bay. Researchers are hopeful that the astonishing sighting means that the waters in the Bay are finally getting healthier.

Although there is no record of an attack on humans, great white sharks have been observed inside the Bay on several occassions. A study by the Stanford Tagging of Pacific Pelagics documented several tagged sharks entering and exting the Bay in a study published in the Proceedings of the Royal Society in 2009.

Five white sharks entered the Bay over a period of two years, one shark entering four times. The only documented white shark fatality in San Francisco came on May 7, 1959, when Albert Kogler Jr., 18, died while swimming in less than 15 feet of water after he was attacked off Baker Beach, about one mile west of the Golden Gate Bridge.

“For me its pretty exciting and a sign that the health is returning to the San Francisco Bay ecosystem. We swim in the Bay every day at the Dolphin Club without a shark encounter. Its why we call this month Sharktober.” said McGuire. “The risk of shark attack is extremely low. Over eighty swimmers from the Dolphin Club and South End Rowing Club swam from Alactraz last week, and another race is scheduled for next weekend. It is up to the leadership what to do, but I suspect this shark is well fed.”