NASA Astronaut <a href="https://en.wikipedia.org/wiki/Dorothy_Metcalf-Lindenburger" class="extiw" title="en:Dorothy Metcalf-Lindenburger">Dorothy Metcalf-Lindenburger</a>, commander of the NEEMO 16 underwater exploration mission, dives into the water off Key Largo at the beginning of Mission Day 1 (June 11, 2012).  The NEEMO 16 mission is being conducted at Aquarius Reef Base, the world's only underwater laboratory.  NASA photo in public domain.
NASA/Kris Kehe
<a rel="nofollow" class="external free" href="http://www.nasa.gov/mission_pages/NEEMO/gallery/neemo16_metcalf-lindenburger.html">http://www.nasa.gov/mission_pages/NEEMO/gallery/neemo16_metcalf-lindenburger.html</a>