This Poem Is a Complete Jumble and Beyond Explanation

You may find these waters too shallow

For you to sail through. Too bad for you.

The only creatures at my window

Are milling crowds of curious leaves,

And I am floating over the green

Of them, like they were weeds in a stream,

Like the swimmer that I used to be.

This window creates the barrier

That has become my glass-bottomed boat,

And I am observing carefully

These inquisitive, inhuman crowds

Sunk in light, glad to see no one’s drowned.