Never mind Fabian Cousteau,
how about under the ocean on one of Saturn’s Moons
Have a close look at this image of Titan. That blue haze around Titan is an atmosphere and that makes Titan a very interesting prospect for searching for life. The atmosphere makes its warm enough to sustain a moon ocean- not water, but methane. Now a new cosmic concept proposes to send a submarine to Titan and search this ocean for signs of primitive life.