"When inferior to the enemy, and you have only a squadron of observation to watch and attend upon their motions, such a squadron should be composed of two-decked ships only [that is, ships of the highest mobility] as to assure it purpose. It must have the advantage of the enemy in sailing, else under certain circumstances it will be liable to be forced to battle or to give up some of its heavy sailers. It is highly necessary to have such a flying squadron to hang on the enemy's large fleet, as it will prevent their dividing into separate squadrons for intercepting your trade or spreading their ships for a more extensive view. You will be at hand to profit from any accidental separation or dispersion of their fleet from hard gales, fogs, or other causes. You may intercept supplies, intelligence, &c, sent to them. In fine, such a squadron will be a check and restraint upon their motions, and prevent a good deal of the mischief they might otherwise do." Three years before, when first called to be Chief of the Staff in the Channel, he had emphasised the same points. "Much," he wrote in July 1779, "I may say all, depends upon this fleet. 'Tis an inferior against a superior fleet. Therefore the greatest skill and address is requisite to counteract the designs of the enemy, to watch and seize the favourable opportunity for action, and to catch the advantage of making the effort at some or other feeble part of the enemy's line; or if such opportunities don't offer, to hover near the enemy, keep him at bay, and prevent his attempting anything but at risk and hazard; to command their attention, and oblige them to think of nothing but being on their guard against your attack."[21] [21] _Barham Papers_, i, 292. It was on these lines the war was conducted. The West Indian area, in which lay the enemy's principal object, was treated as the offensive theatre and the home waters as the defensive. Inferior as was the Channel fleet to the home fleet of the allies, its defensive operations proved adequate to prevent their achieving any success. Nor was this all, for Kempenfelt was able to demonstrate the positive side of his theory in the most brilliant and convincing manner. In dealing with concentration we have seen how, in command of such a flying squadron as he postulated, he was able off Ushant to seize a favourable opportunity for action, which resulted in his capturing a convoy of military stores essential to the French operations in the West Indies under the nose of De Guichen with an escort of nearly twice his force.