Lake Union Professional Review and Guide
"The origins of Lake Union go back 12,000 years. The lake was carved by the Vashon glacier, which also created Lake Washington. The Duwamish people called it “small lake.” In 1854, pioneer Thomas Mercer predicted there would be a “union of waters” with canals connecting it to Puget Sound. Bill Boeing began his airplane company on the lake in 1915.
The modern Lake Union is home to marinas, floating homes, dry docks, Gasworks Park, and a seaplane terminal. Many paddlers in Seattle have taken their first strokes there as summer water temperatures can rise into the 70s. A tour of Lake Union could be combined with excursions either east to Portage Bay, the Washington Park Arboretum, and Lake Washington, or west along the ship canal toward the Hiram M. Chittenden Locks."