I grew up on the ocean and one of the most comforting "at home" feelings is being out past the breakers, disconnect my board leash, and just dive deep down, exhale enough air out my lungs to stop floating, and just sit on the ocean floor for a few seconds in beautiful silence.
And then stupid lungs run out of air and I have to resurface.
Edit: And I'm sure that sounds scary to some, but trust me, the water, ocean, and surf are like a best friend that's not scary at all once you get to know it. Quite the opposite.