On 25 Sept. the Lennox parted from the fleet and returned to England with a convoy of empty victuallers. In the following spring she took the trade out to Lisbon, returning to the Downs by the end of April. In May she was with the Channel squadron cruising between Ushant and Scilly. In July she went out to the Mediterranean with the Levant trade; in October and November she was at Smyrna; in December she returned to England, and was paid off on 13 March 1703–4. Vernon had already been appointed to the Barfleur, flagship of Sir Clowdisley Shovell [q. v.], which he now joined, and in her went out to the Mediterranean, and was present in the battle of Malaga. In December he was moved into the Britannia, Shovell's flagship in the Mediterranean, and at the capture of Barcelona in 1705. On 22 Jan. 1705–6 he was made captain of the Dolphin frigate, and ten days later was moved into the Rye, which he commanded in the Mediterranean during 1706 and 1707, returning to England in October with the fleet commanded by Shovell, but escaping Shovell's fate. On 21 Nov. 1707 he was moved from the Rye to the Jersey of 50 guns, which he took out to the West Indies in the following April, and commanded on that station for the next four years, under Commodore (afterwards Sir Charles) Wager [q. v.] and Commodore James Littleton [q. v.], whom he helped to break up a Spanish squadron off Cartagena, July 1710, and with whom he returned to England in the autumn of 1712. In March 1715 he was appointed to the 50-gun ship Assistance, one of the fleet in the Baltic under Sir John Norris [q. v.] in 1715–16, and under Sir George Byng [q. v.] in 1717. She was paid off on 22 Oct. 1717, and for the next eighteen months Vernon was on half-pay. In March 1719 he was appointed to the Mary, a 60-gun ship, and was again with Norris in the Baltic in the summers of 1719–1720–21. He then went on half-pay, and in 1722 was returned to parliament as member for Penryn. In April 1726 he was appointed to the 70-gun ship Grafton, one of the fleet in the Baltic that summer under Sir Charles Wager, and in 1727 under Norris. In the winter she joined the fleet under Wager, at Gibraltar, and returned to England in May 1728, on the conclusion of hostilities with Spain.
It is now not difficult to see that the treaty of Seville insured a speedy renewal of war. Its commercial clauses necessarily led to smuggling on the one hand, to violent repression on the other. The well-known case of Robert Jenkins [q. v.] occurred in 1731, and there were others of a similar kind both before and after. Rear-admiral Stewart, the naval commander-in-chief, could see that the fault lay largely with the merchants at Jamaica (Engl. Hist. Review, iv. 742–4); but at home the merchants whose goods were seized could make their complaints heard in parliament, and the angry feeling against the Spaniards gave Walpole's enemies a definite point of attack on the government. In these debates Vernon distinguished himself by his vehement invective. He specially insisted on the weakness of the Spanish colonies; and as Porto Bello was the most hateful of these, being the port from which the guarda-costas fitted out, he urged that Porto Bello should be destroyed. Nothing but determination was needed; it might be done, he himself would undertake to do it, with six ships. It was natural to believe that in promoting Vernon to the rank of vice-admiral, 9 July 1739, and appointing him to the command of an expedition to the West Indies, the government was gladly getting rid of a man who had made himself obnoxious (Campbell, Lives of the Admirals, iv. 8); but though this consideration may have had weight, Vernon was not only an officer of longer service and more active experience than any other then available, but was also well and favourably known to Wager, at this time first lord of the admiralty, and to Norris, admiral of the fleet, and in daily consultation with Wager. Far from being, as has been supposed, a mere parliamentary job, Vernon's appointment may be fairly considered as due mainly, if not entirely, to the recommendation of these two men, with whom he had long served.
No declaration of war was made till 19 Oct.; but on 19 July Vernon received his instructions ‘to destroy the Spanish settlements in the West Indies and to distress their shipping by every method whatever;’ and on the 23rd he put to sea with eight ships of the line and one frigate. The frigate and three of the line-of-battle ships were, however, detached for independent service on the coast of Portugal, and it was with only five ships that Vernon arrived at Jamaica, where he was shortly afterwards joined by Commodore Charles Brown [q. v.] in the Hampton Court. This gave him exactly the six ships that had been spoken of, and with these he came off Porto Bello on the night of 20 Nov. The next morning the squadron stood in to attack, the Hampton Court leading. The fortifications were nasty enough to look at. The entrance of the harbour was narrow and was commanded on the left hand by the Iron Castle (San Felipe
