“This prison barge at Guantanamo Bay is available for 3,000 prisoners”
It appears to be property of NYC and is still there. If it wasn’t being used as a jail, it certainly could have ben used for Covid-19 patient recovery...
https://en.wikipedia.org/wiki/Vernon_C._Bain_Correctional_Center
https://citylimits.org/2018/05/10/urbanerd-the-history-of-the-citys-floating-jail/
Thanks