That crisp, clear seawater you paddle in isn't as as pure as you might think. Magnify it 25 times, and you'll find that it's full of life.
This image was captured by David Littschwager and explained in detail by Dive Shield. It shows a single drop of seawater at 25 times magnification, and allows you to see the crab larva, diatoms, bacteria, fish eggs, zooplankton, and even worms that share a dip with you. It's good to know you have friends at sea with you. [David Littschwager and Dive Shield via Lost at E Minor via This Is Colossal]