I’m looking for a new favorite spot in CT. Lakes or slow, calm rivers, or marshlands. My go to is Pachaug, which I love, but I want to explore. Any advice would be appreciated! 
Housie
One of my favorite day trips is floating down the Housatonic and exploring the maze of salt marshes at its delta at Long Island Sound, then paddling back up to the put in. You can paddle out into the Sound a ways too along the coast. I 've blanked out on the name of the bridge where we put in - it’s a handsome arched stone one. The paddle upriver is nice on a moonlit night - there is enough “civilization” ambient light along it. and little traffic. Bring a cable lock to secure your boat to the pier and there are a couple of docks below resstaurants where you can stop for supper. I like the mix of wild area, semi-urban and coastal paddling this outing affords. Be sure and bring a whistle because it is easy to lose track of each other in the marshes. The grasses are way too tall to see over and there are dozens of braided channels.