Elizabeth made naval strength a high priority. She risked war with Spain by supporting the "Sea Dogs", such as John Hawkins and Francis Drake, who preyed on the Spanish merchant ships carrying gold and silver from the New World. The Navy yards were leaders in technical innovation, and the captains devised new tactics. Parker (1996) argues that the full-rigged ship was one of the greatest technological advances of the century and permanently transformed naval warfare. In 1573 English shipwrights introduced designs, first demonstrated in the "Dreadnaught", that allowed the ships to sail faster and maneuver better and permitted heavier guns. Whereas before warships had tried to grapple with each other so that soldiers could board the enemy ship, now they stood off and fired broadsides that would sink the enemy vessel. When Spain finally decided to invade and conquer England it was a fiasco. Superior English ships and seamanship foiled the invasion and led to the destruction of the Spanish Armada in 1588, marking the high point of Elizabeth's reign. Technically, the Armada failed because Spain's over-complex strategy required coordination between the invasion fleet and the Spanish army on shore. Moreover, the poor design of the Spanish cannons meant they were much slower in reloading in a close-range battle. Spain and France still had stronger fleets, but England was catching up. Parker has speculated on the dire consequences if the Spanish had landed their invasion army in 1588. He argues that the Spanish army was larger, more experienced, better-equipped, more confident, and had better financing. The English defenses, on the other hand, were thin and outdated; England had too few soldiers and they were at best only partially trained. Spain had chosen England's weakest link and probably could have captured London in a week. Parker adds that a Catholic uprising in the north and in Ireland could have brought total defeat. Colonising the New World The discoveries of Christopher Columbus electrified all of western Europe, especially maritime powers like England. King Henry VII commissioned John Cabot to lead a voyage to find a northern route to the Spice Islands of Asia; this began the search for the North West Passage. Cabot sailed in 1497 and reached Newfoundland. He led another voyage to the Americas the following year, but nothing was heard of him or his ships again. In 1562 Elizabeth sent privateers Hawkins and Drake to seize booty from Spanish