Inside Passage, a coastal water route between Seattle, Washington, and Skagway, Alaska. Most of it is along the British Columbia coast. The passage, about 950 miles (1,530 km) long, affords a protected shipping route that largely avoids the open sea. It follows relatively calm straits and sounds between the mainland and hundreds of offshore islands and often zigzags between islands. Abruptly rising mountains, evergreen forests, snowcapped peaks, and glaciers make it a scenic route. The passage is open the year round. Passenger ships ply the passage in summer.