Berween the under and the upper blue

I have been missing the ocean ever since I left it--one week ago.

It was a glorious day, glorious!

Seagulls

Between the under and the upper blue
All day the seagulls climb and swerve and soar,
Arc intersecting arc, curve over curve.

And you may watch them weaving a long time
And never see their pattern twice the same
And never see their pattern once imperfect

Take any moment they are in the air.
If you could change them, if you had the power,
How would you place them, other than they are?

What we have labored all our lives to have
And failed, these birds effortlessly achieve:
Freedom that flows in form and still is free.

Robert Francis

Collected Poems: 1936-1976, 
University of Massachusetts Press, 1976, page 161.

Last night's poem by Robert Bly has only twelve lines also,
but in four-line stanzas instead of three-line ones. It is interesting to compare the two poems in terms of structure and tight construction.
What do you see??