A little while back, there was a video showing an underwater house, and it was reported that people could actually live there if they chose to. It's a see-through house that has most of what a person would need to survive in it, but, of course, the person would have to wear some type of breathing apparatus since they'll be living in the middle of the sea and would most likely want to go outside of the house sometimes.
It's an interesting idea or invention, but it's just not worth the risk of being swallowed up by the big bad sea.