Sit on the Left side of the plane for the best views on flights from Seattle to Boston. Left side wins both departure and arrival. During the cruise over the northern Rockies and Great Lakes, the left side also faces slightly more northward, offering better views of the Cascades, northern Montana ranges, and the Great Lakes shoreline depending on exact routing. Right side has little to compete with at either end of the flight.

During takeoff from Seattle Tacoma International (SEA), sit on the Left side for the best views. SEA primarily departs northbound on runways 16L/16R or southbound on 34L/34R. On a northeastbound departure to Boston, aircraft typically climb out heading east or northeast, putting the left side facing north toward downtown Seattle, Elliott Bay, and the Olympic Peninsula across Puget Sound. The right side faces south toward Tacoma and less distinctive terrain. Notable sights include: Elliott Bay and downtown Seattle skyline, Mount Rainier to the southeast (visible from both sides but better framed left), Puget Sound and the Olympic Mountains to the west, Lake Washington.

When landing at General Edward Lawrence Logan International (BOS), sit on the Left side for the best views. Logan Airport sits on a peninsula in Boston Harbor and typically lands on runways 04L/04R or 22L/22R depending on wind. Arriving from the west on an eastbound approach, aircraft often fly over the Boston metro before turning over the harbor. The left side picks up the Charles River, Cambridge, and downtown Boston's Financial District and Back Bay, while the right side faces south toward Quincy and the South Shore. Notable sights include: Downtown Boston skyline and Back Bay, Charles River and Cambridge, Boston Harbor islands, Logan Airport peninsula approach over the water.

The flight from Seattle Tacoma International (SEA) to General Edward Lawrence Logan International (BOS) takes Approximately 5 hours 15 minutes to 5 hours 45 minutes westbound headwinds considered; eastbound typically 5 hours to 5 hours 30 minutes.

Northern Rocky Mountains over Idaho and Montana, the Continental Divide, the vast agricultural plains of North Dakota and Minnesota, Lake Superior's western tip and southern shoreline, Lake Michigan visible to the south, the Adirondack Mountains of upstate New York on descent into Boston