Moody and Mammoth

The first two stanzas give me a very clear picture but I'm afraid I was lost on what bodies you're talking about when the wind blows east -- I'm sure if I were in Lowell I'd understand. 

I'm not sure why you change tenses during the second stanza.  This gives the impression that you're talking about a specific event which split the pavement -- if you're not, then I have to say it's not working for me (and if you are, I don't know what it is).   The image of the Merrimack is strong, only I'm left thinking that if teeth are covered by lips you don't really see the teeth anyway -- what about lips being drawn back, in rictus perhaps?  I'm not sure where the ship is placed, is it actually in the water?  If so, then you have teeth framed by the river.  

I'm sorry, I really want to get a clearer picture because it's so promising and I've got no real reference.  

Welcome back, Mike, are you sticking around?