Aquanaut (noun)

A person who lives and works underwater in an underwater habitat, such as a submarine or research station.

Origin:

From aqua- meaning water and -naut meaning sailor or traveler, meaning someone who travels in water.

Examples:

1. The aquanauts were trained to live and work underwater for extended periods of time.
2. The aquanauts were conducting research on the ocean floor, studying the effects of pollution and overfishing.
3. The aquanauts were amazed by the diverse and thriving ecosystem they encountered underwater.
4. The aquanauts had to be highly trained in underwater operations, as well as in emergency procedures.
5. The aquanauts were part of a growing field of underwater research, exploring the frontiers of our oceans.