In the preface to the first edition of Modern Seamanship, Rear Admiral Austin M. Knight of the United States Navy made an offhand prediction that captures one of the great technological transitions of the industrial age — and gets it both spectacularly right and quietly wrong.

Knight was writing about why the older seamanship classics by Luce, Nares, and Alston were becoming inadequate. The reason, he explained, was straightforward — they had been written for a world of sail, and the world had moved on. But the old books, he conceded, still had life in them:

"The admirable treatises of Luce, Nares, and Alston, originating in the days when seamanship was almost wholly concerned with the fitting and handling of vessels under sail, have preserved through later editions the general characteristics which they naturally assumed in the beginning. These treatises will never be out of date until the time, still far in the future, when sails shall have been entirely driven out by steam."

Knight was a serious naval thinker — President of the Naval War College, commander of the Asiatic Fleet, and author of the standard American text on seamanship for a generation of officers. When he wrote in 1917 that sail's complete eclipse was "still far in the future," he was hedging an obvious trend. The great merchant clippers were already gone. Steam had been winning since the 1860s. But ocean-going commercial sail wasn't finished yet — the last commercial sailing barques carried grain from Australia into the 1940s. Knight's "far in the future" turned out to be roughly thirty years.

What he got wrong is more interesting. He framed the transition as binary — sail versus steam — and assumed steam was the endpoint. He couldn't have known that within a generation, steam itself would be largely driven out, displaced by oil-fired diesel motors that made the great triple-expansion engines he was helping codify look as quaint as a clipper's royals. By the 1970s, the steamship was as obsolete as the windjammer.

And here's the twist Knight would have found astonishing — sail is coming back. Not for romance, but for fuel economy and emissions:

• Oceanbird, a Swedish project, is designing wing-sail cargo ships that look like floating skyscrapers.
• Cargill has fitted WindWings — rigid 37-meter sails — to bulk carriers, reportedly cutting fuel use by ~30%.
• The International Windship Association tracks dozens of vessels operating with wind-assist technology in 2026.

The IMO's tightening emissions rules have done what nostalgia never could — they've given the wind an economic argument again. Knight's "far in the future" complete victory of steam never quite arrived. Instead, fossil fuels won a hundred-year interregnum, and now the oldest power source is sneaking back onto cargo decks under a different name.

His old seamanship books, by his own logic, may not be fully out of date yet.