The SS Selma, is a World War I reinforced concrete tanker scuttled decades ago off the coast of Galveston, Texas, and visible above the water line.
Since 1992, besides recognition with a Texas Historical Commission's Official Texas Historical Marker, she has been designated as a State
Archeological Landmark by the Texas Antiquities Committee, as the Official Flagship of the Texas "Army", and is listed on the National
Register of Historic Places. In addition, the SS Selma rests in a significant site in Galveston Bay, the bay near the "marine battleground"
for part of the Civil War's Battle of Galveston in 1863.

Because steel was in short supply during the war, concrete was proposed as a viable alternative material for use in ship building.
The Selma, a 7500 ton reinforced concrete tanker built in Mobile, Alabama, was launched on June 28, 1919. She was one of several concrete ships
conceived and designed during World War 1. Construction was not completed until the war ended. She had a length 420 ft., a beam of 54 ft.
and a draft with full cargo of 26 ft.. Her loaded displacement was 13,000 tons. This vessel marked the first use of shale aggregate expanded
in rotary kilns for lightweight structural concrete.