For those wondering if they could pull it off this video gives an idea of how it might have been.
It's a departure from RW31 looking out of the left cabin windows. Manhatton and central park come clearly into view at 2mins 30secs, quickly followed by the river at 2mins 50secs. By this stage presumably the crew were well on their way down (and thus the view much more challenging).
It brings a lump to the throat realising the only option left to do is to whack it round to the left and go for a southerly ditch. For a light aircraft, I guess Central Park itself might be an option (has any aircraft ever landed there?)
YouTube - TAKE OFF FROM LA GUARDIA AIRPORT NEW YORK