He was promoted to Rear Admiral of the Red on 18 January 1705, and sent to escort a convoy of merchant ships to Lisbon the following month, hoisting his flag in the . On arrival in the Tagus, he placed himself under the command of Sir John Leake and, on , had a principal share in dealing with the French squadron that was blockading Gibraltar. The French force, consisting of five ships of the line, fled on the approach of the much larger British fleet. In the ensuing Battle of Cabrita Point, Dilkes led the capture of the sixty-gun , whilst the remaining French vessels were either captured or destroyed. On , Sir Cloudesley Shovell arrived in Lisbon with reinforcements, and Dilkes remained through the summer with this grand fleet under the joint command of Shovell and Lord Peterborough. He took part in the successful siege of Barcelona before returning to England with Shovell in November.