I’m on a mission, and I’m asking for your help. I’m researching the boat that Fidel Castro used to “invade” Cuba in 1956. Granma was her name, and her 1,200-mile voyage from Mexico to eastern Cuba marked the beginning of the Cuban Revolution. She had belonged to an American businessman living south of the border who sold her to a Castro supporter.

Cuba is replete with academics and historians, so Granma’s story is well documented post-1956, but none of the Cuban chroniclers has shown much interest in the boat’s origins. Maybe I haven’t read the right book or talked to the right person yet. Specifically I would like to know who built Granma.

The 92-year-old man who bought her from the American and turned her over to Castro tells me that she was built in New Orleans. The Mexican bill of sale says the boat was built in 1943 — smack in the middle of World War II, when U.S. shipyards were turning out military craft almost exclusively.

So did Granma begin her life in the military? The hull kind of has that look. But look closely at her traditional sheer. It sweeps upward to the bow, unlike most small Army and Navy craft of the war. Certainly PT boats and even “crash boat” rescue craft sported the reverse sheer that has characterized many recreational powerboats since. Many of these military boats were repurposed as recreational craft after the war, but no amount of civilian modification was likely to change their sheerlines.

Higgins Industries of New Orleans was busy in 1943 churning out PT boats and the famous Higgins landing craft that “won the war.” Did the company have the time or inclination to produce a one-off yacht? Or was the 1943 date on the bill of sale incorrect? (Another written source put Granma’s completion in 1939.)

I’ve cast a wide net, seeking an answer to this most basic question. What American shipyard begat Granma, a tough little ship that changed the world? If you have any thoughts, reply here or send an email to me at [email protected]. This is the beginning of a hell of a story.