In the 1960s, the U.S. Navy was exploring the other "final frontier" -- the sea. A series of underwater habitats called "Sealabs" were constructed for scientific exploration on the ocean floor.

Inside, the habitat resembled a modest RV, with basic amenities such as a shower, toilet, sink, dinner table ... its legacy lived on. During the Cold War, the Navy built special compartments on ...

Inside, the habitat resembled a modest RV, with basic amenities such as a shower ... During the Cold War, the Navy built special compartments on submarines to act as mini habitats for saturation ...