Such close blockade offers various possibilities of damaging the enemy, if the coast fortifications are so constructed with a view to the offensive that the fleet may rally under their protection, and thus gain an opportunity of advancing from their stations for offensive operations. Such possibilities exist on our north coast, and our efforts must be turned towards making the most varied use of them. We must endeavour by renewed and unexpected attacks, especially by night, partly with submarines and torpedo-boats, partly with battleships, to give the blockading fleet no breathing-time, and to cause it as much loss as possible. We must not engage in a battle with superior hostile forces, for it is hardly possible at sea to discontinue a fight, because there is no place whither the loser can withdraw from the effect of the enemy's guns. An engagement, once begun must be fought out to the end. And appreciable damage can be inflicted on the enemy only if a bold attack on him is made. It is only possible under exceptionally favourable circumstances--such, for example, as the proximity of the fortified base--to abandon a fight once begun without very heavy losses. It might certainly be practicable, by successful reconnoitring, to attack the enemy repeatedly at times when he is weakened in one place or another. Blockade demands naturally a certain division of forces, and the battle-fleet of the attacking party, which is supposed to lie behind the farthest lines of blockade and observation, cannot always hold the high seas in full strength. The forces of the defending party, however, lie in safe anchorages, ready to sally out and fight.