In the wild, I've come close - or close enough - to otters. Never this close, a chance afforded me by the thick plastic separating me from three otters at the Monterey Bay Aquarium.

The fur of the sea otter is the most dense of any animal in the world. Its fur can contain up to almost one million strands per inch. The fur is made up of longer waterproof guard hairs and a shorter underfur. The longer hairs keep the dense underfur dry. That combination keeps cold sea water away from the skin of an otter.