In Meredith you are seeing either the open water from the aquatherms at the town docks, or the current from the inlet.
Winnisquam I am not experienced on, but I know the section of frequently open water you are probably talking about, visible from Rt3. That's a narrow section and I'm sure it has a current.
Currents can form around islands, and particularly in a shallow strait, like between 2 islands, or that case, points in the mainland.
|