[5] Based on the subjects of his paintings, he likely travelled and visited many Mediterranean ports such as Lisbon, Genoa, Malta and Sicily.
These works formed the nucleus of the Dulwich Picture Gallery, England's first public art gallery-museum.
[6] His marine paintings cover the whole range of subjects typical for marine painters in the 17th century such as sailing ships and galleys at sea, port scenes, Mediterranean port capricci, ships in distress, storms at sea and naval battles.
This painting may have been inspired by the frequently reproduced line engraving after the design of the Flemish artist Stradanus of 1590.
The work, which depicts the defeat of the Turkish naval force by a European coalition in 1571, is undated but was likely painted around 1683, the year that the Turks unsuccessfully laid siege to Vienna.
The port town and the many persons onshore are painted in detail making it possible to recognize a Knight of Malta.
Engravings made by John Smith after designs by Castro show that he may also have produced genre scenes (National Portrait Gallery, London).