If you’ve ever cruised between Bimini and Cat Cay, you’ve surely found yourself alongside the wreck of the SS Sapona. When I first visited the skeletal remains of this 282-foot freighter, I marveled. Despite being built in 1920 and wrecked in 1926, her bow and superstructure still stand after a century of battering by wind and waves. There’s a reason: Sapona is built of concrete.
Yup, concrete. In the 1910s, American shipbuilders experimented with a lattice of steel with concrete poured around it called ferrocement. During World War I, needing steel for warships, tanks, and guns, President Woodrow Wilson approved 24 ferrocement cargo “Liberty Ships.” During World War II, Tampa’s McCloskey shipyard was commissioned to build 24 300-foot ferrocement freighters.
Ferrocement hulls were lighter than steel—and more fragile. In 1920, Sapona’s sister ship Cape Fear collided with City of Atlantaoff Narragansett. Cape Fear “shattered like a teacup,” drowning 19 crew. Yet ferrocement was also incredibly durable. Even today, you can see hulls like the wave-pounded SS Palo Alto in Aptos, California. J. E. Sawyer lies just off the USS Yorktown in Charleston. The Atlantus still rises off Cape May, NJ, while at Virginia’s Kiptopeke State Park and on British Columbia’s Powell River, huge concrete ships serve as breakwaters. One of the Powell “hulks,” the still-afloat USS Quartz, was a supply vessel during 1946 atomic tests at Bikini Atoll.
In 1966, a team of California entrepreneurs, including boxer/actor/pro golfer Joe “Palooka” Kirkwood, towed McCloskey freighter R.L. Humphrey—rechristened Jalisco—from San Francisco to California’s infamous Cortes Bank. They intended to create a ferrocement island nation in the Bank’s 6-foot-deep waters, but their November arrival coincided with a mammoth swell. Clutching a foremast before being blasted into the sea, Kirkwood gaped. Looming above, he wrote, was “an enormous wall of blue-green water rising 45 feet or more, the fish in it plainly visible.”
Today, surfers, divers, and fishermen glide above boils created by Jalisco’s hull.
After plans to turn Sapona into a South Florida casino failed, she was towed to Bimini by a one-armed British army veteran and rum runner named Bruce Bethell. There, she was scuttled in shallow water, serving for Prohibition liquor storage and as a fish market. She also became a popular diving, angling, and fighter plane target practice site. On December 5, 1945, Flight 19—five Avenger torpedo bombers bearing 14 crew—took off from Fort Lauderdale. After targeting Sapona, the pilots made for home, but became disoriented amidst worsening weather. Flight leader Lt. Charles C. Taylor’s last radio transmission came hours later: “All planes close up tight … we’ll have to ditch unless landfall … when the first plane drops below 10 gallons, we all go down together.”
They were never heard from, or seen, again.
This article originally appeared in the January 2026 issue of Power & Motoryacht magazine.
