Anchorage for Boston Fireworks?

[Klem]

We have watched fireworks in many different harbors but have never been in Boston for the 4th because of not knowing where to watch them from. Does anyone know of a good anchorage for watching the Boston 4th of July fireworks from? Since they are set off over the Charles, it seems like the usual places that we anchor won't be good as we would be looking over the city. I have heard of people taking dinghies up through the locks but we will likely have more people than can fit in our dinghy and I don't want to deal with the madhouse at the end (I have paddled down the Charles from upstream to watch them before and seen what happens at the end of the show). Any tips would be appreciated.