The Sea Dogs were essentially a military branch that were authorised by the Queen to attack the Spanish fleet and loot their ships in order to bring back riches and treasure. They carried "Letters of Marque" which made their plundering of Spanish ships legal under English Law despite not being at war. The Sea Dogs were started in 1560 as a way to bridge the gap between the Spanish Navy and the English Navy. By having a small fleet of ships that would sail around and pick off Spanish ships, risking their lives and own ships in the process, they were able to reduce the funds and size of the Spanish navy significantly. The Sea Dogs continued carrying out raids against the Spanish until 1604 when England and Spain made peace. After that, many of the Sea Dogs continued as pirates employed by the Barbary States, in what would become the Anglo-Turkish piracy in the Caribbean.
Sir Francis Drake, El Draque (The Dragon), was one of the most profitable and successful sea dogs of all time. The captain of Golden Hind, he served in the English Navy from 1563–1596 and achieved the rank of Vice Admiral. Drake was trained early on in the maritime arts by Sir John Hawkins, his cousin and fellow slave trader. Drake also was the second man in history to circumnavigate the globe; robbing the Spanish fleet the whole time. Drake also had a huge range of coverage, raiding up the Spanish on the Pacific Coast all the way up to modern day San Francisco. Drake was a master pirate. Not only did he commandeer ships but he also would sail into ports in the Caribbean and put ransoms on cities. After doing this he would begin burning the city down until he received payment. Drake was awarded a knighthood in the year of 1581. He later died of dysentery after an unsuccessful attempt to take San Juan, Puerto Rico.
Sir John Hawkins was born into a wealthy family where his father was a sea captain. Hawkins initially sailed with his father on trading trips, but by 1562 he became “England’s first slave trader” using his fleet of three ships led by the "Jesus of Lübeck" to aggressively take 400 Africans from Guinea, Africa, and sold them in the West Indies. He traded in slaves for about five years, making three voyages to Sierra Leone and Guinea and selling 1,200–1,400 African slaves to the Spanish. Queen Elizabeth I gave him a Coat of arms which featured a bound slave.
Sir Walter Raleigh was another important Sea Dog. A favorite of the queen, he received a title that allowed him to claim any land that he discovered in the name of England. During an expedition to the New World, he founded the colony of Roanoke. This colony, however, ended up disappearing mysteriously. Raleigh became infatuated with the idea of a "city of gold" hidden somewhere in South America and set out on an expedition to find it. On his second expedition to find "El Dorado", he ended up in a bit of a predicament after men under his subordinate Lawrence Keymis looted a Spanish Outpost. After this outrage, Raleigh went back to England, and the Spanish were not very happy with what Raleigh's men did in violation of the extant peace treaties. In order to make things right to the Spaniards, Raleigh was executed in the reign of King James I Stuart (1566–1625).
However, after years of picking off and looting by English Sea-Dogs, he decided that he had had enough. King Philip took his whole armada of 130 ships into the English Channel and decided to attempt to end English sea-raiding for good. The Spanish ships were bigger and more heavily armed, but the English ships were smaller, faster, and more manœuvrable.
Concurrently, there was a huge storm that came in while the Spaniards were on their way and the Spanish suffered terrible losses. They ended up retreating after losing more than half of their original ships.
DUDLEY, W. G. (2013). ELIZABETH'S SEA DOGS. Military History, 30(4), 56–63