"Dreadnought" sailed for the Mediterranean Sea for extensive trials in December 1906 calling in at Arosa Bay, Gibraltar and Golfo d'Aranci before crossing the Atlantic to Port of Spain, Trinidad in January 1907, returning to Portsmouth on 23 March 1907. During this cruise, her engines and guns were given a thorough workout by Captain Reginald Bacon, Fisher's former Naval Assistant and a member of the Committee on Designs. His report stated, "No member of the Committee on Designs dared to hope that all the innovations introduced would have turned out as successfully as had been the case." During this time she averaged , slowed only by a damaged rudder, an unprecedented high-speed performance. This shakedown cruise revealed several issues that were dealt with in subsequent refits, notably the replacement of her steering engines and the addition of cooling machinery to reduce the temperature levels in her magazines (cordite degrades more quickly at high temperatures). The most important issue, which was never addressed in her lifetime, was that the placement of her foremast behind the forward funnel put the spotting top right in the plume of hot exhaust gases, much to the detriment of her fighting ability.