That is freaking impressive.
Then they somehow manage to land on shore without getting smashed AND have to climb the mountain to the other side of the island.
Fact certainly outdoes fiction in the Shackleton sage.
They came very close to getting smashed up in a storm, all while they were running low on potable water.
The main reason they had to hike over the island was because they were so thirsty when they finally reached shore that they all ran to a stream to drink and waves hit the James Caird and broke the rudder, rendering it worthless to sail around to the inhabited side of the island.