It separates the borough of Queens on Long Island from the Bronx on the North American mainland, and also divides Manhattan from Queens and Brooklyn, which is also on Long Island. Because of its connection to Long Island Sound, it was once also known as the Sound River.Click to see full answer. In this regard, which direction does the East River flow? The East River is Not Actually a River While inland rivers travel in one direction, the East River’s direction of flow changes with the time of day; sometimes, you’ll find it heading North-East to Connecticut, and other times, it’s flowing South to New Jersey.Furthermore, can you swim across the East River? Generally speaking, it is legal to swim in the Hudson or the East River, the Police Department told us. It is illegal, however, to enter restricted areas in the water or interfere with boat traffic. You also need permission from the landowner where you enter the water. Herein, where does The Great Gatsby take place? Long Island How deep is the East River in NY?Actual main channel depths along the river vary; with a least depth of 24′ or less at a few locations at the channel edges to a maximum depth of 108′ being found mid-channel at the southern approach to Hell Gate.