When the day goes down on Watertown

The story:

Watertown, MA, is an inner ring suburb about eight miles west
of downtown Boston. When this song came out, I was in college
in the Boston area, so I associated the song not with the generic
sea port Hornsby intended, but specifically with Watertown. This
despite Watertown not having any docks other than possibly the
kind you use to get in an out of a rowboat: although the Charles
River runs through Watertown, at that point it isn't navigable by
anything bigger than an eight-man rowing shell, if that.