A quarter of a mile? That's not bad. When George Anson lead his expedition against the Spanish in 1740, after they had rounded Cape Horn, they were trying to find the island of Juan Fernandez. In a conference with his officers, he reluctantly agreed to sail east. Then, a few days later, the lookout in the trestle trees said he could see the snow-capped mountains of the Andes. They came about and sailed west until they found Juan Fernandez. More than 200 men died of scurvy in his squadron thanks to that map error. One ship sailed into the sheltered waters of the island under the loom of the land, but then the breeze failed them. The men were too weak to man the longboats and tow her in. Dozens of men died of scurvy within site of the island before enough men who had already landed regained enough strength to pull out and tow the ship in.
We live a pretty coddled existance compared to people even a few centuries ago. Anson set sail with more than 2000 sailors and soldiers, in a squadron with six warships and two supply ships. He returned to England by circumnavigation a little over three years later with slightly more than 200 of the original complement (they hired Dutchmen in Cape Town to sail her home) in Centurion
, the only surviving ship.
Of course, they took the Alcapulco treasure galleon, and brought back almost one and half million gold and silver coins, and roughly a half ton of silver ingots, not counting the other minor plunder they'd taken. The survivors were set up for life, literally.