The Prisoner's Breath

In an air shell, a transparent casing,
the vast sea is only an echo passing.
There is no white foam, nor salt that lives,
but a blue thought, a fleeting pulse arrives.
And in the silence, a wave begins to creep,
a never-reached longing, a secret deep.
It yearns to shatter, that distant blue heart,
but stays closed fast, an airy dream apart.