Raft

"You did read the Accords before you signed them, right?" "Of course." "So you know that if you break the agreement, the law states I have to turn you over to Secretary Ross, and he won't hesitate to detain you on The Raft for the foreseeable future." "I don't like boats." "It's not really a boat. It's more like a floating prison."

- Jeffrey Mace and Yo-Yo Rodriguez

The Raft is an underwater prison created for the sole purpose of detaining and incarcerating enhanced individuals.

History
"Give me a break, Barton. I had no idea they'd put you here. Come on." "Yeah, well, you knew they'd put us somewhere, Tony." "Yeah, but not some Supermax floating ocean pokey, you know. This place is for maniacs, it's a place for-" "Criminals. Criminals, Tony. I think that's the word you're looking for. Right? It didn't use to mean me. Or Sam, or Wanda. But here we are."

- Tony Stark and Clint Barton

As the Clash of the Avengers ended, Falcon, Scarlet Witch, Hawkeye and Ant-Man captured by Iron Man's team and taken to the Raft for working outside the law. Tony Stark flew to the Raft to tell Sam Wilson that he believes Steve Rogers' story about Helmut Zemo. Tony landed on the raft and was greeted by Thaddeus Ross. Stark watched on a monitor showing Maximoff in her cell. Stark then made his way to where his former allies were being held. Tony was then mocked by Clint Barton calling him 'the futurist', but Stark tells Barton that they shouldn't be in there as the Raft was built for maniacs and criminals, which Barton claimed that they are all now. Stark then walked past Scott Lang who said that you can never trust a Stark which Stark came back by not knowing who he is. Tony Stark continued to make his way to Sam Wilson to ask where Steve Rogers is so he can help him. Wilson asked how Rhodes was after his crash. Stark told Wilson that he believed Rogers and that he needed his help to tell him where Rogers and Barnes had gone. Wilson told Stark and he left to go to Siberia. As Stark was leaving, Thaddeus Ross asked if they said anything, which Stark lied about and made his way to Siberia.

The Inhuman Elena “Yo-Yo” Rodriguez was threatened by S.H.I.E.L.D. Director Jeffrey Mace, to be sent to the Raft if she went against the Sokovia Accords, where she replies that she doesn't like boats, with Director Mace telling her that it's "like a floating prison".

Escape from the Raft
"My faith is in people, I guess. Individuals. And I’m happy to say for the most part, they haven’t let me down. Which is why I can’t let them down either. Locks can be replaced, but – maybe they shouldn’t."

- Steve Rogers to Tony Stark

Later, Steve Rogers knowing he couldn't let down the people who stood by him, infiltrated the facility and freed Clint Barton, Wanda Maximoff, Sam Wilson and Scott Lang.

Former

 * Sam Wilson
 * Clint Barton
 * Wanda Maximoff
 * Scott Lang

Trivia

 * In the comics, the Raft is an island prison for super-powered criminals located near Ryker's Island.
 * This version of the Raft also replaces Prison 42, a massive prison located in the Negative Zone used by Tony Stark, Hank Pym and Reed Richards to contain non-registered superhumans as they waited for their trials in the original "Civil War" storyline.
 * The 2016 X-Men series film  had a deleted scene in which the villain Ajax is transported out of a prison called "The Raft". Due to copyright issues with the prison name, the scene was removed from the final cut.