Lone Woman of San Nicolas's cave is found

An October 2012 story in the LA Times describes the recent discovery of a cave on San Nicolas Island that archaeologists believe sheltered the Lone Woman of San Nicolas.

The story of the Lone Woman was immortalized by Scott O'Dell in his book "Island of the Blue Dolphins".  A fictionalized account of the Lone Woman, whose Native American name was never known, the book tells the tale of a young woman named Karana who survives alone on a remote island for nearly twenty years.

The remarkable sea otter

From Wikipedia

The small square of fur was silky smooth and buttery soft. The surface hairs were deep brown, long and supple. Underneath, short fuzzy hairs cushioned my hand as it rested on the fur. It was 2004, I was at the Monterey Bay Aquarium, and I was petting a piece of sea otter fur. 

Why is sea otter fur so remarkable?