We have been working our way through the series and came across S10E7 on the escape from Alcatraz. The idea that they stole an electrical cord and used it to pull their raft behind a police boat was one of the stupidest ideas I have heard. Even Josh's attempt showed how it could never have worked.
There were many problems with it.
- It was during the day
- The tides likely were not the same
- I think they used a rope and not a '60s electrical cord
- Worst of all, they used a modern raft, and even it broke
I'm basing this off the Mythbusters episode where they attempted the escape themselves and proved it was plausible. They built a raft and life vests from rubber raincoats, used wooden paddles, attempted the crossing at night, and chose the right time to best match the tides. They actually made it to the mainland near the Marin Headlands.
During their crossing, they said they had to blow air in every 10 minutes so it barely survived being paddled. If it had been towed behind a boat, they wouldn't have made it 20 feet before it was torn to shreds.
The rest of the episode could be possible, but towing their raft behind a boat was not.