Through the Maelstrom

You can't have a second copy on board. Once you have claimed one, you can't launch another, make progress at your opponent's copy or claim it: it is scored only once.

It happens for the player who claims it, whoever launched it, and at once: claims happen in the battle step, after the crew destroyed there are gone (706.6). Choose a crew on board when it happens, your opponent's; you may choose none, and with none, nothing happens. The crew goes back to its owner's hand: it isn't destroyed, and it loses its damage, markers and bonuses. A token stops existing (801.12).

In your own watch, while this card is in your scrapyard, you may pay the cost to put it on board. It isn't deployed: no one can react to it. It is launched again in the middle, with no progress.

Crew dispatched here on their own turn make progress, whoever launched it; on the opponent's turn they can only fight (706.3a). The first player to reach 8 progress claims it and gains 3 spoils.