When the main mast fell, Thomas had been in his quarters. The ink from his quil had barely touched the parchment – getting only as far as “My dearest Clara” before the relentless swells upended his cabin. The loud snap of the main mast’s wood sounded like one of the canons being fired. Waves nearly six meters high bombarded the ship's wooden hull like a boxer delivering blow after blow. 

The water in his cabin was nearly waist-high. Thomas waded across the tiny room, scrambling to...