British naval strategy imparted numerous responsibilities upon the Royal Navy, including the seizing of the enemy's colonial resources, the defence of the nation from invasion and the protection of British supplies from overseas.
Control of the sea was largely maintained by frigates, which could operate as reconnaissance vessels, perform convoy duty, and fight in ship-to-ship actions. Ships of the line did not cruise the seas in this manner, but rather performed blockade duty and, when possible, confronted the enemy in fleet actions. This, indeed, was a fleet's raison d'etre: to bring a rival fleet to battle and destroy it.
Once engaged with the enemy, general strategy gave way to the more technical art of tactics - the actual methods employed to defeat the enemy in battle. British tactics were based on the line of battle, which required an admiral to draw up his fleet in one or two lines, usually with the flagship in the centre and the frigates stationed on the unopposed side, so distributed along the line as to be capable of repeating orders from the flagship to the rest of the fleet before the engagement began. The enemy would also form a line, and the British attack would come either obliquely or in parallel, with, theoretically, every ship engaging an opponent of equal or weaker strength. By employing such tactics, the maximum strength of each ship's broadside could be brought to bear. Prior to action, the admiral would already have decided whether he wished to attack with the weather gauge or the lee gauge. the side with the weather gauge, by which the wind blew one's force in the direction of the enemy, could almost invariably make contact with an opponent, whether he wished to engage in combat or not. The side with the weather gauge also provided the attacker with the opportunity to double the enemy's line (i.e. to attack him from both side simultaneously) or pass through or break his line. On the other hand, the fleet with the lee gauge could allow its weaker or damaged ships to leave the line when necessary. Moreover, the heel of the ship, which elevated the trajectory of the guns on the lower deck, allowed the vessel's lower-deck ports to remain open longer, and provided more opportunities for firing on the enemy, the angle of whose opposing guns being depressed would not allow continuous fire. In short, a fleet determined to engage an enemy always favoured the weather gauge, whereas a fleet seeking the lee gauge normally did so to be sure of surviving an action, not least through the option of escape.
In most of the major actions of the French Revolutionary and Napoleonic Wars the British sought to break or otherwise disrupt the enemy's line, and therefore sought the weather gauge. Contrary to popular belief, the notion of breaking the enemy's line was not original to Nelson, nor even a product of the battle of the Saintes in 1782, penetrated the French line in an unprecedented feat later repeated in similar style at the Glorious First of June (1794), Camperdown (1797), St Vincent (1797) and, of course, most famously at Trafalgar (1805). In all these instances British tactics were invariably aggressive, with admirals and captains taking the initiative to attack, confident that their better-trained crews, even when faced by a numerically superior foe, would carry that day.