The use of smoke screens provided a factor which had been absent in previous attempts in history.
Mention has already been made of the great deterrent afforded by the presence of hostile batteries and of the varying degrees of efficiency of gun-fire as a defence against attacks from the sea. If smoke could be utilised in such a manner as to hide the attacking force from the batteries without completely blinding the former, and if at the same time the attack could be made under cover of darkness so as to prevent aircraft from assisting those batteries, a set of conditions less unfavourable to the attackers would then be forthcoming. Obviously, this necessitated the smoke drifting shorewards ahead of the approaching vessels; i.e., the assistance of a wind blowing more or less directly towards the shore.
It is well here to caution the reader against a commonly erroneous idea in this connection. It is often supposed that the use of smoke was a sort of panacea for all evils, that it provided a counter to all obstacles. This was very far from being the case, as will now be explained. Firstly, let us consider the navigational difficulties. Smoke could not possibly assist the ships to avoid shoals when approaching the coast. Smoke could not prevent the vessels from being seen and reported by surface patrol craft, submarines, or aircraft during the trip across the sea. The danger from mines could not be avoided by the use of smoke. It has already been pointed out that it is quite difficult enough to locate one's destination on a dark night when the lighthouses have been extinguished and other navigational aids withdrawn. Even a landsman will realise that if, as an addition to such inconvenient conditions, one places an artificial fog between the approaching vessels and their destination the problem is not going to become any more easy to solve. The utmost that one could gain from the use of smoke was some measure of protection from the shore batteries, but, as just shown, such use provided a further obstacle to be surmounted. Then again there is nothing so fickle in the life of a sailor as the wind. If the wind died away or changed to an off-shore direction, smoke might be practically useless for covering one's approach.
I have sometimes been asked why we made no use of poison gas clouds. There were two main reasons. The last thing we desired was to risk killing those downtrodden Belgians who were still allowed to reside in their unhappy country. In addition to that, the fickleness of the wind might waft the poison gas in the direction of our own vessels.
Surprise Essential
With regard to the element of surprise and the use of diversionary measures, one of the principles laid down by Stonewall Jackson is, "Always mystify, mislead, and surprise the enemy." The meaning of surprise is apt to be misconstrued. In an operation of this kind one could not arrange for the blockships to arrive suddenly "as a bolt from the blue" at a moment when the enemy have no suspicions whatever that any trouble is brewing. Thus, surprise and mystification had to go hand in hand. The only practical method in such cases, whether in trench warfare or in sea fighting, is to give the enemy as much to think about as one possibly can, to make him wonder what on earth is going to happen next, to mislead him into believing the eventuality is very different from that intended, and, then, as the late war expression so aptly puts it, "when the enemy has the wind up," surprise him by carrying out your main object in view.
Diversionary measures in this particular case were not difficult to evolve. Many different reasons obtained for employing our sea forces off the Flanders coast. To mention a few, there were bombardments from the sea, landing operations on the shore, supporting the flank of the military in their land attacks, mining or mine-sweeping operations, laying submarine traps, supporting aerial attacks, and so on. The presence of our vessels might indicate any one of these objects and each would call for a different set of defensive measures.
The full development of defensive measures cannot be attained until one can clearly ascertain the attacker's object. Even when the latter has been discovered, the time required to bring all your powers of defence into action must vary according to how far you have just previously been misled. Our best course, therefore, was to ensure that our object would be discovered so late in the proceedings that it would be attained before full advantage of the discovery could be utilised. Initiative usually pertains to the attacking force. Where the defence is open to several different forms of attack, the defending commander is apt to be so apprehensive beforehand, and so perplexed at the time, that his position will be weakly defended at all points. As the attack develops and he receives an apparent indication of its object he will make haste to concentrate all his defence measures at the threatened position, and then, if the attackers have acted wisely, there is considerable likelihood of his being taken by surprise too late to guard efficiently against the real blow. Uneasy lies the head of the commander who is forced to adopt the defensive role in war.
The diversionary measures actually undertaken will be described presently.
Attention to Detail