Largest concrete ship still afloat

Ships with a concrete hull have been built since the mid-nineteenth century. The largest still afloat is the SS Peralta, which is 128 m long with a beam of 15.4 m and a gross tonnage of 6,144. She was originally built as an oil tanker and launched in 1921. She is still afloat and serves as a floating breakwater to protect a log storage area on the Powell River, British Columbia, Canada.