sentences:  The sonnet's imagery of sea going vessels ("proud full sail") recalls the mighty galleons of the Spanish Armada that fought the British fleet of smaller, more nimble ships.The image of a galleon at full sail sailing in the direction of some treasure, invites admiration for the strength of the rival's poetry, and for the size of his ambition.This image is diminished in the second quatrain, when it is suggested that the rival is merely co-author along with his "compeers", and it is diminished further in the third quatrain when the rival is shown to be duped ("which nightly gulls him") by those "spirits".