THE UK's first ever underwater "city" has been unveiled with Mars-grade tech and tiny homes deep under the sea. The underwater habitat dubbed Sentinel, is designed to house people at depths of 650ft ...

They can stay underwater for an hour, but come to the surface to breathe. So, ocean habitats are large and wet. Ooh, I'm off to find a boat. Create a picture of an ocean habitat. On the back ...

THE UK's first ever underwater "city" has been unveiled with Mars-grade tech and ... to pop out into the ocean to empty the tank. The number of people that a Sentinel habitat can hold varies ...