The above linked article from 2014 tells about the Alcatraz escape on June 11, 1962. We’ve heard about this escape over the years, where three men made a rubber raft of raincoats and attempted to paddle out of the San Francisco Bay.
They tell about the tests that were attempted by Mythbusters back in 2003. The video is interesting to watch. Depending on the time they left, they may have made it. Some evidence shows that they did.
Here’s the Wikipedia article on the escape: The Escape. There is a lot of information there.
Part of why they think that the men didn’t make it to shore had to do with being in the water for a long length of time. So many people do a similar swim annually, that I think that it was possible. The speed that they’d have to go would be not an unreasonable speed in a boat. I think there’s a good chance they made it. One day we might know?