“We roped ourselves together as a precaution against holes, crevasses, and precipices, and I broke trail through the soft snow. With almost the full length of the rope between myself and the last man we were able to steer an approximately straight course, since, if I veered to the right or the left when marching into the blank wall of the fog, the last man on the rope could shout a direction. So, like a ship with its “port,” “starboard,” “steady,” we tramped through the fog for the next two hours.”

— Ernest Shackleton, South