Departure Vision shows all NYP departures heading west toward Newark and beyond, including Amtrak trains. That will work for heading that direction, It does not show departures heading east toward New Haven and Boston. One trick would be to have an idea when the eastbound Amtrak train left Newark, then assume NY Penn arrival about 15-20 minutes later. Look and listen for an arriving eastbound Amtrak in the mid-teens tracks. Odds are, that's it.