"With ships the sea was sprinkled far and nigh"

WITH ships the sea was sprinkled far and nigh,

Like stars in heaven, and joyously it showed;

Some lying fast at anchor in the road,

Some veering up and down, one knew not why.

A goodly vessel did I then espy

Come like a giant from a haven broad;

And lustily along the bay she strode,

Her tackling rich, and of apparel high.

The ship was nought to me, nor I to her,

Yet I pursued her with a lover's look;

This ship to all the rest did I prefer:

When will she turn, and whither? She will brook

No tarrying; where she comes the winds must stir:

On went she, and due north her journey took.

This sonnet has always haunted me, without my thinking much about why.  But today I realized it's the amazing twelfth line.  All the other lines are end-stopped (or could be) with no sentences ending midline.  But then we get that amazing caesura, just in the question about when the ship would turn: "When will she turn, and wither?"  And then the only enjambment, as she does turn, and another clausal ending after "tarrying" in line 13.  You read the last three lines as a kind of three line poem-within-the-poem, and they're pure blank verse in this Petrarchan sonnet.  The sense of enjambed, even Miltonic, blank verse -- except that it's purely Wordsworthian -- overlays and displaces the sonnet form that contains it, and that's what the ship is doing too -- brooking no tarrying, commanding the winds, sailing due north.