Case file · High strangeness
Dougherty Island, which 'has melted'
In 1841 Captain Daniel Dougherty of the whaler James Stewart reported an island at 59°20′S 120°20′W; two other captains claimed to confirm it, but it does not exist.
1841 CE · -59.33, -120.33 · status: explained
The account
Nobody ever landed on it. After searches in the early 20th century found nothing, Captain John King Davis of the Nimrod remarked that the island had probably melted, suggesting the sightings were of fog or ice. It stayed on some maps until 1934.
The sceptical view
A large tabular iceberg or a low fog bank, seen from a distance, matches every description.