Not only were kayakers paddling down the East River this weekend, but the Roosevelt Island Twitterverse reports:

In February 2012 , Roosevelt Island resident Dave Rosenberg saw what looks like the same submarine part on a barge

Image From Dave Rosenberg passing Roosevelt Island asking:

what the heck is that?

Mike Giroux answered:

I think it’s the tail section of a Virginia-class submarine. Look at the diagonal fin on the bottom, then look at the back of the sub in this picture:
http://www.globalsecurity.org/…

(At first I thought it was the tail of a Seawolf, but they’re not building any more of those, apparently – the Virginia’s are smaller and cheaper)