Lake Washington Ship Canal begun in 1906, and work began in earnest five years later. The delays in canal planning and construction resulted in the U.S. Navy building the Puget Sound Naval Shipyard in Bremerton, Washington, which is located across the Sound from Seattle. For centuries, people had been dragging boats between the lakes, giving names like "carry a canoe" "sxWátSadweehL" to the crossing points. In 1854 Seattle pioneer Thomas Mercer proposed canals connecting Lake Union and Lake Washington to Puget Sound in a speech at the first Independence Day celebration of the Seattle area's first permanent white settlement, shortly after its founding. Mercer
Puget Sound Central Basin. Puget Sound's sills, a kind of submarine terminal moraine, separate the basins from one another, and Puget Sound from the Strait of Juan de Fuca. Three sills are particularly significant—the one at Admiralty Inlet which checks the flow of water between the Strait of Juan de Fuca and Puget Sound, the one at the entrance to Hood Canal (about below the surface), and the one at the Tacoma Narrows (about ). Other sills that present less of a barrier include the ones at Blake Island, Agate Pass, Rich Passage, and Hammersley Inlet. The depth of the basins is