All summer long, a crimson and white boat moves back and forth through the waters near the Port of Alaska collecting silt, sand and gravel off the seafloor to allow vessels to navigate the harbor in Anchorage. The boat is a dredging vessel called the Westport, operated by Manson Construction of Seattle, Wash., which the U.S. Army Corps of Engineers – Alaska District contracted to maintain the mooring areas for the past three years.