John Cabot—the second European to step foot on North America in 1497, disappeared along with his five ship fleet during an expedition to find a western route from Europe to Asia.
This was, after all, 1499, when things like the Coast Guard and GPS was not yet around to help someone out of such situations. Still, it is unusual that nothing was heard again from at least one of the ships from the ill-fated cruise, but such was the case with Mister Cabot's fleet.