NASA flight surgeon/aquanaut <a href="https://en.wikipedia.org/wiki/Josef_Schmid_(flight_surgeon)" class="extiw" title="en:Josef Schmid (flight surgeon)">Josef F. Schmid</a> (center) and NASA astronaut/aquanaut <a href="https://en.wikipedia.org/wiki/Jos%C3%A9_Hern%C3%A1ndez_(astronaut)" class="extiw" title="en:José Hernández (astronaut)">José M. Hernández</a> (right) practicing cave-reel techniques while training for the May 2007 NEEMO 12 mission. On left, Aquarius Reef Base aquanaut <a href="https://en.wikipedia.org/wiki/Mark_Hulsbeck" class="extiw" title="en:Mark Hulsbeck">Mark Hulsbeck</a> assists Schmid and Hernández.  NASA photo JSC2007-E-21804.
NASA
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