concentration could be effected from a distance. The power to effect it had to be sought by a judicious choice of position. The "line ahead" had been imposed on sailing fleets by the need to bring each ship's broadsides into action. Experiments made during manoeuvres by steam navies, combined with the experience gained in the war of 1904–05 in the Far East, showed that no material change had taken place in this respect. It was still as necessary as ever that all the guns should be so placed as to be capable of being brought to bear, and it was still a condition imposed by the physical necessities of the case that this freedom could only be obtained when ships followed one another in a line. This allowed each ship to fire over wide arcs without firing over friendly ships. Steaming with the enemy off to the side enabled a ship to fire salvoes with both the forward and rear turrets, maximizing the chances for a hit. When in pursuit or flight, or when steaming on the look-out for a still unseen enemy, a fleet may be arranged in the "line abreast". A pursuing fleet would have to run the risk of being struck by torpedoes dropped by a retreating enemy. But it would have the advantage of being able to bring all its guns which can fire ahead to bear on the rear ship of the enemy. When an opponent was prepared to give battle, and turns his broadside so as to bring the maximum of his gunfire to bear, he must be answered by a similar display of force – in other words, the line ahead must be formed to meet the line ahead. Each ship in the line generally engaged its opposite number in the enemy battle line. The layout of gun turrets on a deck affects their permissible sectors of fire. The most common configuration of warship with gun turrets on its longitudinal axis severly limits gunfire directly ahead (forward) or abaft (backward). This was reflected in a standard naval tactics of crossing the t. Introduction of camouflage Dazzle camouflage was intended to make it difficult to estimate a ship's speed and heading and thus prevent submarines from effectively firing torpedoes. This was accomplished by painting striking designs along the ship, with long, bold lines frequently cutting across the hull and thus rendering the bow of