Around 8:45 p.m. Thursday night, just as one of the last ferries was leaving Alcratraz with 438 passengers on board, a distress call went out about a 31-foot recreational boat with 10 people on board that had hit a rock and was taking on water. Captain Erik Anfinson, a.k.a. Captain Tubby, decided to redirect the boat immediately to perform a rescue. "Just as we got there the boat started taking on enough water to the point where we wanted to make sure we got everybody off," Anfinson tells ABC 7.

The small craft struck what's known as Little Alcatraz, an outcropping near the prison island that famous for causing shipwrecks, as CBS 5 reports, because it's only visible at low tide.

The rescue took a matter of minutes, saving the 10 people, as you can see in the Facebook video above, from having to spend any time in the 54-degree water of the Bay. They were all gathered calmly on the bow of the motorboat, and Anfinson explains to the Chronicle that he's performed similar rescues before, but never with so many people.

Lacking a rope long enough to tie the smaller boat up to the ferry, Anfinson said, “I maneuvered the [ferry] right up alongside of it. We had the two boats rafted up basically side by side, not tied together.”

Lt. Nicole Emmons with the Coast Guard tells the Chronicle, "It was a good thing [Anfinson] heard our broadcast and went over there and helped them out."

All 10 passengers made it safely onto the Alcatraz Tours ferry and were taken back to Pier 33 without injury. As you can hear in the video above, some of the 438 Alcatraz tourists on the ferry erupted into cheers when the rescue was complete — and shortly thereafter the sinking boat was submerged underwater.

"I'm just doing my job. That's what we're trained to do," said Anfinson to ABC 7.