The U.S. Navy used to do much the same thing transferring personnel from ship to ship via 'highline' in a 'boatswain's chair'. 'Have no idea if that's still done.
I saw more than one guy get soaked by wave action while crossing between two ships that were 'rolling' slightly in fairly heavy seas!
Since I have the backbone of a chocolate eclair, that wouldn't have been be something I'd have wanted to do!