The whole campaign serves well to show what was understood by concentration at the end of the great naval wars. To Lord Barham and the able admirals who interpreted his plans it meant the possibility of massing at the right time and place. It meant, in close analogy to strategic deployment on land, the disposal of squadrons about a strategical centre from which fleets could condense for massed action in any required direction, and upon which they could fall back when unduly pressed. In this case the ultimate centre was the narrows of the Channel, where Napoleon's army lay ready to cross, but there was no massing there. So crude a distribution would have meant a purely defensive attitude. It would have meant waiting to be struck instead of seeking to strike, and such an attitude was arch-heresy to our old masters of war.
So far we have only considered concentration as applied to wars in which we have a preponderance of naval force, but the principles are at least equally valid when a coalition places us in inferiority. The leading case is the home campaign of 1782. It was strictly on defensive lines. Our information was that France and Spain intended to end the war with a great combined effort against our West Indian islands, and particularly Jamaica. It was recognised that the way to meet the threat was to concentrate for offensive action in the Caribbean Sea everything that was not absolutely needed for home defence. Instead, therefore, of trying to be strong enough to attempt the offensive in both areas, it was decided to make sure of the area that was most critical. To do this the home fleet had to be reduced so low relatively to what the enemy had in European waters that offence was out of the question.
While Rodney took the offensive area, Lord Howe was given the other. His task was to prevent the coalition obtaining such a command of home waters as would place our trade and coasts at their mercy, and it was not likely to prove a light one. We knew that the enemy's plan was to combine their attack on the West Indies with an attempt to control the North Sea, and possibly the Straits of Dover, with a Dutch squadron of twelve to fifteen of the line, while a combined Franco-Spanish fleet of at least forty sail would occupy the mouth of the Channel. It was also possible that these two forces would endeavour to form a junction. In any case the object of the joint operations would be to paralyse our trade and annoy our coasts, and thereby force us to neglect the West Indian area and the two Spanish objectives, Minorca and Gibraltar. All told we had only about thirty of the line on the home station, and though a large proportion of these were three-deckers, a good many could not be ready for sea till the summer.