I found this , can any tell me what this means "Droits of the Crown"

The battle
At dawn on 5 October, the Spanish frigates sighted the coast of Portugal. At 7 a.m. they sighted the four British frigates. Bustamante ordered his ships into line of battle, and within an hour the British came up in line, to windward of the Spaniards and "within pistol-shot".
Moore, the British Commodore, sent Lieutenant Ascott to the Spanish flagship Medea, to explain his orders. Bustamante naturally refused, and impatient of delays, at 10 a.m. Moore ordered a shot be fired ahead over the bows of Medea. Almost immediately a general exchange of fire broke out. Within ten minutes the Mercedes was destroyed when her magazine exploded, and only about 40 of her 240 crew were rescued. Within half an hour the Santa Clara and the Medea had surrendered, and the Fama broke away and attempted to flee, pursued by the Medusa. Moore ordered the faster Lively to pursue, and she was also captured a few hours later. The three frigates were taken to Gibraltar, and then to Gosport, England.
[edit] The results
Spain declared war on Great Britain on 14 December 1804, only to suffer a catastrophic defeat less than a year later at the battle of Trafalgar in October 1805. Napoleon, having crowned himself Emperor on 2 December, gained Spain as an ally in his war against Britain.
Under the terms of the Cruizers and Convoys Act of 1708 ships captured at sea were "Droits of the Crown" and became the property of their captors, who received the full value of the ships and cargo in prize money. However, since technically Britain and Spain were not at war at the time of the action, the Admiralty Court ruled that the three ships were "Droits of the Admiralty", and all revenues would revert to them. The four Spanish ships carried a total of 4,286,508 million Spanish dollars in silver and gold coin, as well as 150,000 gold ingots, 75 sacks of wool, 1,666 bars of tin, 571 pigs of copper, seal skins and oil, although 1.2 million in silver, half the copper and a quarter of the tin went down with the Mercedes. Still, the remaining ships and cargo were assessed at a value of £900,000 (equivalent to £60,810,000 today.[1]). After much legal argument an ex gratia payment was made which, according to one account, amounted to £250,000. If so, each of the four Captains