Transition is also called liminality by psychologists - a state where you are neither in the state you left nor entirely in your new state. This in-between state creates an identity crisis, even in good transitions.
But they are really a predictable and integral part of life and happen regularly. Author Bruce Feiler interviewed hundreds of people and found that a major life change happens, on average, every 12 to 18 months. Even huge collective transitions such as the pandemic occur with regularity.
Since ancient times, humans have assigned healing and transformational properties to water. In early Rome, baths were an important part of cultural life, a place where citizens went to find relaxation and to connect with others in a calming setting.
The sound around us, from an auditory perspective, is simplified. It's not quiet, but the sound of water is far more simple than the sound of voices or the sound of music or the sound of a city.
The visual input is simplified. When you stand at the edge of the water and look out on the horizon, it's visually simplified relative to a city you're walking through, where you're taking in millions of pieces of information every second.
The water could be inducing a mildly meditative state of calm focus and gentle awareness.
When we're by the water, our brains are held in a state of mild attentiveness. In this state, the brain is interested and engaged in the water, taking in sensory input but not distracted by an overload of it.