We own the digitized archives of the Royal Geographical Society. It contains the Sir Ernest Shackleton Collection (scroll down to find it). In this collection, you can view, for example, “Sketch map drawn on menu card to illustrate proposed journey across Antarctic continent, 7th March 1914,” or “Page torn from an almanac by Shackleton and carried by him for navigation purposes, 1915-16, from the sinking of the ‘Endurance’ to Buenos Aires.”
You may want to recommend the RGS archive if you receive questions relating to this week’s discovery of the wreck of Shackleton’s ship, the Endurance!