Penn and Venables, were
promptly clapped by Cromwell into the Tower on their return. This
stroke against Spain amounted to a declaration of war, and on Blake's
return to England he was ordered to blockade Cadiz. One detachment
of the plate fleet fell into the hands of his blockading ships and
the silver ingots were dispatched to London. Blake continued his
blockade in an open roadstead for six months, through autumn and
winter, an unheard of thing in those days and exceedingly difficult.
Blake was himself ill, his ships were not the copper-bottomed ones
of a hundred years later, and there was not, as in later days, an
English base at Gibraltar. But he never relaxed his vigilance.

In April (1657) he learned that another large plate fleet had arrived
at Santa Cruz, Teneriffe. Immediately he sailed thither to take or
destroy it. If Porto Farina had been regarded as safe from naval
attack, Santa Cruz was far more so. A deep harbor, with a narrow,
funnel entrance, and backed by mountains, it is liable to dead
calms or squally bursts of wind from the land. In addition to its
natural defenses it was heavily fortified. Blake, however, reckoned
on coming in with a flowing tide and a sea breeze that, as at Porto
Farina, would blow his smoke upon the defenses. He rightly guessed
that if he sailed close enough under the castles at the harbor
entrance their guns could not be sufficiently depressed to hit
his ships, and as he saw the galleons and their escorts lined up
along the shore he perceived also that they were masking the fire
of their own shore batteries. For the most difficult part of his
undertaking, the exit from the harbor, he trusted to the ebbing
tide with the chance of a shift in the wind in his favor.

Early on the morning of April 20th (1657) he sailed in. As he had
judged, the fire of the forts did little damage. By eight o'clock
the English ships were all at their appointed stations and fighting.
During the entire day Blake continued his work of destruction till
it was complete, and at dusk drifted out on the ebb. Some writers
mention a favoring land breeze that helped to extricate the English,
but according to Blake's own words, "the wind blew right into the
bay." In spite of this head wind the ships that were crippled were
warped or towed out and not one was lost. The English suffered
in the entire action only 50 killed and 120 wounded, and repairs
were so easily made that Blake returned to his blockading stat