Smithtown Bay is a significant estuary and embayment on the north shore of Long Island in Suffolk County, New York, forming a large cove bounded by Eaton’s Neck to the west and Crane’s Neck to the east. It is characterized by a predominantly sandy bottom heavily covered with silt, a result of weak currents and the outflow of brackish water from the Nissequogue River and sediment discharge from Stony Brook Harbor. The bay's depth ranges from just a few feet off the beach to approximately 50 feet as it borders the open waters of Long Island Sound. This environment supports a diverse fishery that shifts with the seasons, drawing anglers for its variety of inshore species. The bay features an artificial reef and several wrecks, adding structural complexity to the otherwise flat bottom. It is a historic fishing ground known for providing a mixed bag of species, often within a single tide.