She was built to carry oil, spent two decades packing sardines, and now spends her retirement holding back the Pacific. The SS Peralta is a ship made of concrete, which sounds like a contradiction until you learn that wartime steel shortages drove engineers to experiment with reinforced concrete hulls during both world wars. At 128 meters long, the Peralta is the oldest and largest American-built concrete ship still afloat, though "afloat" might be generous for a vessel that has not moved under her own power since the 1940s.
The San Francisco Shipbuilding Company launched the Peralta in February 1921, near the tail end of a wartime push to build ships from anything that was not steel. Concrete ships were an engineering curiosity born of necessity: heavy, slow, and difficult to repair, but buildable when conventional materials were scarce. With a beam of 15.4 meters and a reinforced concrete hull, the Peralta was designed as an oil tanker. She was one of several concrete vessels built during and after World War I, part of a fleet that most maritime historians regard as a fascinating dead end in naval architecture.
The Peralta's career as a tanker was short-lived. In 1924, she was acquired and converted into a sardine cannery, spending the next 24 years processing fish in Alaskan waters. The conversion was practical: her massive hull provided ample interior space for processing equipment, and a concrete ship that could not move fast was perfectly suited to sitting in a harbor. After her cannery days ended, the Peralta was moored off Antioch, California, where she sat idle, a hulk without a purpose, waiting for someone to find a use for 128 meters of indestructible concrete.
The Powell River Company found that use in 1958. They bought the Peralta and towed her north to Powell River, British Columbia, where she was moored as the centerpiece of a floating breakwater protecting the company's log storage pond. She joined other decommissioned vessels in the line, including former warships and lumber schooners, creating an unusual barrier of ghost ships along the waterfront. The breakwater shielded millions of dollars' worth of timber from the chop of Malaspina Strait, and the Peralta's concrete hull, impervious to the rot that claimed her wooden and steel neighbors, proved ideal for the job.
When the Powell River mill downsized operations in 2000, someone proposed sinking the Peralta as an artificial reef for divers. The idea was rejected. After the scuttling of YOGN-82, a fellow breakwater barge, in 2018, the proposal resurfaced: perhaps the Peralta could follow her companion to the seafloor. For now, she remains where she has been for over six decades, riding low in the water off Powell River. From the air, the breakwater reads as a dark angular line just offshore, and the Peralta is the longest shape in it. A concrete ship that outlasted the steel ones, still doing her job after a century, still refusing to sink.
The SS Peralta is moored at approximately 49.86°N, 124.55°W as part of the floating breakwater at Powell River, British Columbia. The breakwater line of decommissioned ships is visible from altitude along the waterfront, protecting the former log storage pond. Powell River Airport (CYPW) is nearby to the south. The breakwater is best seen from a low approach over Malaspina Strait. Comox (CYQQ) on Vancouver Island lies approximately 30 nm to the southwest.